SEARCH · PubMed Health

Results for “genotype-phenotype correlation”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources

PubMed1985

Genetic factors and fetal growth sex constitution and birthweight in twins.

Fetal growth is considered a multifactorially-influenced characteristic. Genetic factors were found to play the main role in fetal growth determination, and it is the polygenic inheritance. The paper reviews the birthweights of 360 unlike-sexed two-egg twins, born at the Clinic of Gynecology and Obstetrics, Faculty of Medicine in Beograd, from January 1, 1970 through June 30, 1984. The mean birthweight differences between the male (2954.94 +/- 704.28 g) and female (2313.19 +/- 651.32 g) fetuses, amounted to 141.75 g. The difference is highly significant (P less than 0.01); variation coefficient shows that the examined groups were homogenous (VC was below 30%). The results were discussed from the genetic point of view, and particularly from the point of view of sex constitution, with special respect to the effect of Y chromosome on fetal growth. It has been known that human somatic development, body weight, bone maturation and teeth development are influenced by variety of factors. In addition to nutritional and other factors of the external environment, genetic and humoral factors are leading. The fact that fetuses with XY male constitution are heavier at birth than female fetuses with XX constitution, made us consider the correlation between genotype-phenotype, and the mentioned characteristics. This study was aimed at finding out the role of genetic factors in fetal growth, with respect to sex constitution, particularly to chromosome effect on fetal growth in unlike-sexed two-egg twins.

Birth Weight↗

PubMed2025

Spectrum of genetic variants associated with maple syrup urine disease in the Middle East, North Africa, and Türkiye (MENAT): a systematic review.

BACKGROUND: Maple syrup urine disease (MSUD) is a hereditary metabolic disorder caused by a deficiency in the branched-chain α-keto acid dehydrogenase (BCKD) enzymatic complex. The Middle East and North Africa, and Türkiye (MENAT) region has witnessed a significant rise in the prevalence of MSUD due to high rates of consanguinity. Despite numerous genetic association studies, the complex relationships between genotype and phenotype in MSUD remain elusive. AIM: This study aimed to systematically review the variants significantly associated with MSUD in the MENAT region. METHODS: We systematically searched four literature databases (PubMed, Scopus, Web of Science, and Science Direct) from inception until December 2023 to gather all reported genetic data pertaining to MSUD in the MENAT region. Quality assessment and data extraction were diligently performed by a team of six investigators. RESULTS: A total of 16 studies, involving patients, were included in this systematic review. Among them, 211 patients presented with 105 variants located within genes known to be associated with MSUD. The majority of the identified MSUD variants were found in BCKDHA (38%), followed by BCKDHB (38%), DBT (23%), and PPM1K (1%). Notably, 77% of the captured variants were unique to the MENAT region. CONCLUSION: Our systematic review reveals a distinctive genetic and clinical susceptibility profile of MSUD among individuals from the MENAT region. These findings highlight the importance of understanding the specific genetic landscape of MSUD in this population. Further research is warranted to elucidate the complex genotype-phenotype relationships in MSUD in the MENAT region.

Humans↗

PubMed2026

Two Bacillus PGPB Strains in Wheat and Soybean: Wheat Growth Promotion Without Detectable Rhizosphere Microbiome Restructuring.

Plant growth-promoting bacteria (PGPB) are increasingly deployed as biofertilizers, yet the link between an inoculant's genomic potential and its realized effect on the plant is rarely assessed within an integrative framework that jointly captures the rhizosphere microbiome, plant phenotype, and strain genome. Two Bacillus strains-B. halotolerans 1453 and B. pumilus 630-were applied to wheat and soybean in a factorial pot experiment (2 strains × 2 application methods × 3 frequencies + control, 3-4 replicates). Rhizosphere samples (n = 67 after filtering) were profiled by 16S rRNA sequencing with PICRUSt2 functional prediction and compositional validation (Aitchison PERMANOVA, ALDEx2, ANCOM-BC2). The PGPB gene repertoire was characterized by genome mining (481 marker genes, 14 categories). Wheat phenotype (six traits) and soybean height were analyzed with models appropriate for count data (Negative Binomial and binomial GLMs) for treatment-vs.-control comparisons, and with factorial ANOVA for decomposition into main effects and interactions. Crop identity was the dominant factor shaping both microbiome structure and function (PERMANOVA R2 = 14.7% taxonomically and R2 = 7.8% functionally, both p < 0.001), with biologically meaningful taxonomic differences between wheat and soybean; strain, application count and method had no significant effect on community composition (R2 < 4% each), and co-occurrence networks showed no reliable differences between crops once read depth and sample size were controlled for. Despite this neutrality at the microbiome level, inoculation significantly increased wheat spike count (NB-GLM, all 12 treatments vs. control, padj 0.0002-0.031), ear weight, and stem count, with application count the strongest source of variability and a pronounced strain × application count. Strain 1453 outperformed 630 in spike count (+23.1%, p = 0.012) and ear weight (+20.4%, p = 0.023); we hypothesize that this may be related to its more complete DNRA pathway (narGHI + nirB-nirD) and biocontrol genes (bacE, srfAA). Strain 630 produced a less pronounced effect than strain 1453 but was subject to smaller fluctuations across replicates (CV ≈ 16-21% vs. ≈24-26% for 1453), which may reflect better resilience to environmental fluctuations, possibly due to its confirmed rsbV/rsbW stress-tolerance regulon. Rhizosphere microbiome composition differed clearly by crop (wheat vs. soybean) but showed no detectable response to strain, application method, or application count. Despite this lack of a microbiome signal, inoculation significantly increased wheat spike count and ear weight, with the magnitude and stability of this effect differing by strain. We hypothesize that this strain-dependent difference relates to underlying genomic differences-particularly in nitrogen metabolism (DNRA pathway) and stress-tolerance genes-though this link has not been tested directly and remains a hypothesis for future work.

Triticum↗

PubMed2026

Molecular diagnosis of spinal muscular atrophy: Experience in a pediatric hospital in Argentina.

Introduction. Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease caused by the loss of the SMN1 gene, with a variable clinical spectrum determined primarily by the number of copies of the SMN2 gene. The development of new therapies underscores the importance of early molecular diagnosis and genotype-phenotype characterization. Objective. To describe 27 years of experience in the molecular diagnosis of SMA at a pediatric referral hospital in Argentina and to evaluate the correlation between SMN2 copy number and the SMA types.Population and methods. A retrospective descriptive study was conducted on 1060 pediatric patients with clinically suspected SMA who were evaluated between 1997 and 2024. Molecular diagnosis was performed using PCR-RFLP and, since 2012, MLPA to determine SMN1 and SMN2 copy number. Genotype-phenotype correlation was evaluated in 260 patients with complete clinical characterization. Results. The diagnosis was confirmed in 513 patients. A homozygous deletion of the SMN1 gene was detected in 99.6% of unrelated cases. The positivity rate increased over time. A significant correlation was observed between the number of SMN2 copies and the type of SMA, with milder phenotypes associated with a higher number of copies. Conclusion. Molecular diagnosis of SMA enabled accurate and timely characterization of patients, avoiding invasive procedures and optimizing therapeutic decision-making. Genotype-phenotype correlation is a fundamental tool for prognosis and clinical management, highlighting the importance of an interdisciplinary approach.

Argentina↗

PubMed1995

[A study evaluating the correlation between the phenotype and genotype among 65 cystic fibrosis patients].

Among 65 CF diagnosed patients with both CFTR gene mutations known genotype-phenotype studies were performed. Correlation between pancreatic insufficiency and so called "severe mutations" was found. Respiratory tract symptoms do not seem to depend on one specific mutation as well as meconium ileus is not only limited to the group of patients with delta F508/delta F508 genotype. Some other genotype - clinical features correlation in CF patients are discussed.

Adolescent↗

PubMed1995

The cystic fibrosis transmembrane conductance regulator gene.

Since identification of the gene responsible for cystic fibrosis (CF) in 1989, significant progress has been made in elucidating the mutational basis for this severe, autosomal recessive disease. Such advances have been of major importance in furthering our understanding of the basic defect in CF. Studies of the protein product of the CF gene, referred to as the CF transmembrane conductance regulator (CFTR), indicate that the protein is a Cl- channel but may have additional functions. The most common mutation of the CF gene (delta F508), which leads to the deletion of a single amino acid on the protein molecule, occurs in approximately 70% of CF chromosomes, but the CF Genetic Analysis Consortium has documented over 300 other sequence alterations of the CF gene. In addition to single amino acid deletions, other types of mutations include missense, nonsense (stop codon), frameshift, and splice-junction mutations. Studies of potential correspondences among these different mutational types and predicted functional domains of the CFTR molecule may provide important clues to the physiologic role of normal CFTR and how a defective protein might lead to the CF phenotype. Analyses of genotype-phenotype relationships have shown strong correlations between particular mutations and pancreatic function. However, associations between genotype and severity of CF pulmonary disease are not clear-cut, suggesting that the pulmonary phenotype is strongly influenced by other genetic or environmental factors.

Amino Acid Sequence↗

PubMed2026

Robust replication of associations across patient-mediated and provider-sourced EHR data in the All of Us research program.

The All of Us Research Program is assembling a nationwide cohort with electronic health record (EHR) resources through two complementary pathways: healthcare provider organization (HPO)-sourced EHRs and patient-mediated EHR (PME) contributed through patient portal linkages. The comparative research utility of these two data sources has not been systematically evaluated. Here, we compared PME and HPO EHRs with respect to disease prevalence, phenotype-phenotype associations, and replication of established genotype-phenotype associations using data from 19,703 PME and 373,887 HPO participants. We benchmarked disease prevalence against national estimates, conducted phenome-wide association studies for 10 commonly studied diseases, and tested replication of more than 5000 established genotype-phenotype associations across multiple ancestral groups. Disease prevalence was consistently lower in PME than in HPO, although prevalence of most diseases in both cohorts exceeded national estimates. Both data sources reproduced known phenotype-phenotype associations and showed moderate-to-strong concordance in effect sizes across the phenome. The overall genotype-phenotype replication rate was 49.1% (5399/10,999) in HPO and 5.9% (381/6482) in PME across ancestral groups, with effect sizes strongly correlated among well-powered associations (R = 0.84, P < 0.001). To disentangle the impact of sample size from data quality, we performed 1:1 propensity score matching. After matching, the replication gap in genotype-phenotype associations narrowed from 8.3-fold to 1.3-fold, with equivalent replication rates among adequately powered associations and strongly concordant effect sizes; comorbidity patterns were also consistent across all 10 diseases tested. These findings demonstrate that both data sources are valuable for clinical and genomic research and can inform other cohorts integrating provider-derived and patient-mediated EHRs.

Computational biology and bioinformatics↗

PubMed1991

Genetic structure and the search for genotype-phenotype relationships: an example from disequilibrium in the Apo B gene region.

We analyzed allelic associations (disequilibria) for four restriction fragment length polymorphisms (RFLPs) in the region of the 43-kb Apo B gene in a sample of 233 unrelated individuals from Montreal, Canada, sampled for health. This total sample (T) included 160 individuals of known French Canadian (FC) ancestry. We present a rigorous application of current methodology to these samples, including estimation of type II error probabilities and correlations between markers for estimates of disequilibria. We then consider the utility of these estimates of allelic disequilibria for the interpretation of genotype-phenotype relations. Significant deviations from Hardy-Weinberg equilibrium were not predicted by proximity to other markers in disequilibrium. We found significant quadri-allelic disequilibrium for two marker pairs despite absence of significant deviations from Hardy-Weinberg equilibrium for either marker or tri-allelic disequilibrium, respectively. Altogether these results underscore the complexity of the genotypic structure of the data. A combination of nonevolutionary factors, including sampling for health, small sample size and data exclusion due to methodological constraints of not successfully typing all members of the sample for every RFLP, is a likely explanation for this complexity. These types of factors are common to many RFLP studies. Patterns of composite di-allelic disequilibrium indicated that some RFLP allele pairs may have a longer shared evolutionary history than others and that disequilibrium is not predicted by distance between RFLPs. Type II error probabilities were generally much higher than those for type I errors. Correlations between marker pairs for disequilibria were generally not high. We show from a review of 14 published studies of association between the XbaI RFLP and variation in a total of 15 lipid traits that deviations from Hardy-Weinberg equilibrium can cause substantial differences in the estimation of variability associated with phenotypic differences among marker genotypes relative to Hardy-Weinberg conditions.

Adult↗

PubMed1993

(CTG)n triplet mutation and phenotype manifestations in myotonic dystrophy patients.

A genotype-phenotype study based on the primary clinical features of adult myotonic dystrophy (DM) included 116 patients from 62 Italian pedigrees. A significant correlation between clinical severity and the number of repeats at the 3' untranslated region of the myotonin-protein kinase gene (MT-PK) was found. These results suggest that the CTG amplification is directly related to the myotonic dystrophy phenotype and provide important information on morbidity and prognosis in this disease.

Adolescent↗

PubMed2026

Genetic architecture of endometriosis: risk factors, comorbidities and clinical implications.

BACKGROUND: In 1999, Dr Susan Treloar and colleagues conducted a landmark twin study in Australia and reported their estimate of 51% for the heritability of endometriosis. This important result led several groups to begin mapping genetic factors contributing to increased endometriosis risk. Despite early challenges, advances in genome-wide association studies (GWAS) have identified multiple genetic risk factors and some target genes implicated in follow-up studies on genetic regulation of transcription. Access to large publicly available genetic datasets and analysis with endometriosis GWAS results is also providing new opportunities to answer important questions about comorbid conditions associated with endometriosis and their implications for clinical practice. OBJECTIVE AND RATIONALE: The objective of the review is to summarize the last 25 years of genetic studies in endometriosis, outline contributions to our understanding of the disease, and suggest future directions to accelerate biological insights from genetic studies to improve clinical outcomes. SEARCH METHODS: A comprehensive review of scientific literature on the genetics of endometriosis was conducted through searches in PubMed and Google Scholar up to June 2026. Search terms included "endometriosis AND (genetics OR GWAS OR genetic risk factors)", For studies addressing the functional characterization of genetic risk loci, additional searches employed the terms "endometriosis AND (genotype-phenotype associations OR colocalization OR eQTL OR mQTL OR multi omics methods)". To identify studies examining shared genetic risk between endometriosis and comorbid conditions, the search strategy included "endometriosis AND (genetic correlation OR colocalization OR Mendelian randomisation)". Publications reporting discoveries related to genetic risk factors for endometriosis and studies interpreting their biological and clinical significance were critically evaluated, and 144 publications were discussed in the review. OUTCOMES: Discovery of genetic risk factors started slowly and has accelerated in recent years with developments in technology and international collaborations to combine data and increase statistical power. GWAS have mapped 80 genetic risk factors that implicate gene regulation of hormonal targets, development of the reproductive tract, regulation of cell proliferation, and regulation of epithelial cell differentiation. In common with most other complex diseases, effects of individual common genetic risk factors are small. However, several examples demonstrate that small effect sizes are not a good predictor for the impact of drugs developed against genetically validated targets. Genetic risk factors implicate five genes regulating gonadotrophin release and oestrogen action, the major target pathway of current drugs for treatment of endometriosis demonstrating proof-of-principal for biologically meaningful results. Genetic correlation and Mendelian Randomization studies highlight important causal relationships between endometriosis and comorbid conditions including a possible role for testosterone during development and shared genetic risk factors for gynaecological, gastrointestinal, pain, psychiatric, and inflammatory conditions. Understanding causal relationships between endometriosis and related conditions will aid clinical management and more personalized treatments. WIDER IMPLICATIONS: Genetic studies provide novel insights into endometriosis pathogenesis and associations with related comorbid conditions. Genetic factors modifying gene regulation and disease risk likely act in specific cell types, and access to datasets from genetically informed cell-based models, single-cell and spatial omics data are needed to accelerate progress. Future studies should address critical questions of heterogeneity and disease subtypes, expand the search for genetic risk factors to non-European populations, evaluate the role of rare and structural variants, and better integrate data from functional, genomics, genetics, and clinical studies to reduce diagnostic delay, develop novel treatment strategies, and translate discoveries into personalized management strategies for affected individuals. REGISTRATION NUMBER: N/A.

comorbid conditions↗

PubMed2026

Phylogeographic epidemiology of Dabie bandavirus in East Asia: divergent transmission networks and genotype‑linked clinical severity.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS), caused by Dabie bandavirus (SFTSV), exhibits geographically decoupled incidence and fatality patterns across East Asia. We aimed to elucidate the distinct ecological drivers and phylogeographic dynamics underlying this inland-coastal epidemiological divergence. METHODS: Integrating 1820 high-quality global genomes of SFTSV with well-characterized clinical cohorts (936 patients) and nationwide surveillance data (27,457 cases) from China, we constructed a comprehensive analytical framework. Ecological modeling, Bayesian phylogeography, and genotype-phenotype association analyses were employed to trace the evolutionary trajectories and clinical implications of the virus. RESULTS: A pronounced "inland-high-incidence vs. coastal-high-fatality" pattern of SFTS was identified. The incidence of SFTS exhibited divergent sensitivities to meteorological factors; inland transmission was sensitive to thermal fluctuations, whereas coastal dynamics were constrained by a sunshine threshold (> 200 h/month). In contrast, spatial divergence in clinical severity correlated with the distribution of regional viral genetic structures. Inland regions mainly co-circulated genotypes A, C, and D, while coastal regions were dominated by genotype B. Zhejiang province was identified as a genetic hub with significantly higher recombination frequencies than inland regions (11.0% vs. 3.5%, P < 0.001). Bayesian phylogeographic inference indicated frequent lineage exchange of Zhejiang province in China with the Republic of Korea and Japan. Clinically, genotypes B and D were associated with elevated mortality in coastal and inland regions, respectively, suggesting that the severe coastal phenotype is shaped by its genotype B-dominated structure. Additionally, the RdRp-N828S mutation emerged as a robust molecular correlate of fatal outcomes, warranting further functional validation. CONCLUSIONS: Divergent meteorological factors and plausible maritime transmission networks may underlie the geographically decoupled epidemiology of SFTS. These findings highlight that risk assessment must extend beyond incidence alone and provide a phylogeographically informed framework for targeted surveillance and genotype-specific interventions in high-risk hotspots.

Humans↗

PubMed2024

Species-wide quantitative transcriptomes and proteomes reveal distinct genetic control of gene expression variation in yeast.

Gene expression varies between individuals and corresponds to a key step linking genotypes to phenotypes. However, our knowledge regarding the species-wide genetic control of protein abundance, including its dependency on transcript levels, is very limited. Here, we have determined quantitative proteomes of a large population of 942 diverse natural Saccharomyces cerevisiae yeast isolates. We found that mRNA and protein abundances are weakly correlated at the population gene level. While the protein coexpression network recapitulates major biological functions, differential expression patterns reveal proteomic signatures related to specific populations. Comprehensive genetic association analyses highlight that genetic variants associated with variation in protein (pQTL) and transcript (eQTL) levels poorly overlap (3%). Our results demonstrate that transcriptome and proteome are governed by distinct genetic bases, likely explained by protein turnover. It also highlights the importance of integrating these different levels of gene expression to better understand the genotype-phenotype relationship.

Saccharomyces cerevisiae↗

PubMed2025

Coalescing single-cell genomes and transcriptomes to decode breast cancer progression.

Understanding epithelial lineages of breast cancer and genotype-phenotype relationships requires direct measurements of the genome and transcriptome of the same single cells at scale. To achieve this, we developed wellDR-seq, a high-genomic-resolution, high-throughput method to simultaneously profile the genome and transcriptome of thousands of single cells. We profiled 33,646 single cells from 12 estrogen-receptor-positive breast cancers and identified ancestral subclones in multiple patients that showed a luminal hormone-responsive lineage, indicating a potential cell of origin. In contrast to bulk studies, wellDR-seq enabled the study of subclone-level gene-dosage relationships, which showed near-linear correlations in large chromosomal segments and extensive variation at the single-gene level. We identified dosage-sensitive and dosage-insensitive genes, including many breast cancer genes as well as sporadic copy-number aberrations in non-cancer cells. Overall, these data reveal complex relationships between copy number and gene expression in single cells, improving our understanding of breast cancer progression.

Breast Neoplasms↗

PubMed2026

Twenty-Three Years of Surveillance in Chinese Avian Pasteurella multocida Reveals Declining Antimicrobial Resistance but Increasing Therapeutic Challenges.

Pasteurella multocida (Pm) is an important veterinary and zoonotic pathogen that causes significant economic losses in poultry production. However, long-term surveillance studies integrating antimicrobial resistance (AMR), biocide tolerance, and genomic epidemiology of Pm remain scarce. In this study, we investigated the antimicrobial susceptibility, biocide tolerance, and the phenotypic associations of 136 avian Pm isolates collected from six provinces in China between 2002 and 2024. Whole-genome sequencing was performed to characterize population structure, identify antimicrobial resistance genes (ARGs), and assess genotype-phenotype concordance. The A:L1:ST129 lineage remained the predominant clone throughout the 23-year surveillance period, with a high prevalence of AMR-associated traits observed within this lineage. Although resistance to several commonly used antimicrobial classes declined significantly after 2021, florfenicol resistance continued to increase, suggesting an emerging challenge for the clinical management of pasteurellosis. While the isolates generally exhibited low tolerance to the four representative biocides tested, phenotypic correlations were observed between AMR profiles and biocide tolerance patterns. Furthermore, substantial phenotype-genotype discordance was observed, indicating that the presence of ARGs alone may not be sufficient to accurately predict antimicrobial susceptibility. Overall, this study provides a longitudinal assessment of long-term AMR trends, biocide tolerance, and genomic epidemiology of avian Pm in China, offering epidemiological evidence for monitoring AMR trends and improving antimicrobial management strategies in poultry production.

Animals↗

PubMed2026

Human Monocytic Models Reveal Genotype-Dependent Inflammatory Programs in VEXAS Syndrome.

OBJECTIVES: VEXAS syndrome is a severe X-linked autoinflammatory disorder caused by somatic mutations in ubiquitin-like modifier activating enzyme 1 (UBA1), with clinical outcomes that vary by UBA1 genotype. We aimed to elucidate genotype-specific inflammatory programs and identify potential therapeutic targets. METHODS: We conducted longitudinal deep phenotyping, including whole-blood RNA sequencing (RNA-seq) and clinical activity assessment. Peripheral blood samples were analyzed by single-cell RNA-seq. Human monocytic cell lines harboring each major UBA1 mutation (p.Met41Val, p.Met41Thr, or p.Met41Leu) were generated and subjected to transcriptomic and functional analyses. RESULTS: Thirteen patients with VEXAS syndrome contributed a total of 79 RNA-seq samples. Among genes upregulated in VEXAS syndrome, RNASE1 showed the strongest correlation with longitudinal disease activity (r = 0.70, FDR < 0.05) and was upregulated in patients' monocytes. In UBA1-mutant monocytic cell lines, genotype-dependent ubiquitination defects were observed in a graded manner (p.Met41Val > p.Met41Thr > p.Met41Leu), even in the absence of exogenous stimuli. These defects were accompanied by unfolded protein response activation, increased pro-inflammatory cytokine production, progressive cell death, and RNASE1 upregulation, all following the same graded pattern, recapitulating patient genotype-phenotype associations. Transcriptomic analyses demonstrated enrichment of pro-inflammatory, interferon, and necroptosis signatures in more severe genotypes. Notably, inhibition of receptor-interacting protein kinase 3 (RIPK3) markedly attenuated all pathological features, including RNASE1 upregulation. CONCLUSIONS: Our UBA1-mutant monocytic cell-line models, representing three distinct genotypes, recapitulate genotype-dependent inflammatory phenotypes that can be modulated by RIPK3 inhibition, providing a translational platform for mechanistic investigation and precision therapy development in VEXAS syndrome.

Journal Article↗

PubMed1996

Hereditary tyrosinemia type 1: novel missense, nonsense and splice consensus mutations in the human fumarylacetoacetate hydrolase gene; variability of the genotype-phenotype relationship.

The complete fumarylacetoacetate hydrolase (FAH) genotype of probands of thirteen unrelated families with hereditary tyrosinemia type 1 (HT 1) was established. The screening was performed by analysis of exons 2-14 of the FAH gene by using the polymerase chain reaction (PCR) and of the mRNA by reverse transcription/PCR. Nine different mutations were identified, of which six are novel. Three mutations involve consensus sequences for correct splicing, viz. IVS 6-1 (g-t), IVS 7-1 (g-a) and IVS 12 + 5 (g-a). Two missense mutations (C193R and G369V) and three nonsense mutations (R237X, E357X and E364X) were found. One silent mutation N232N was associated with the skipping of exon 8 from the FAH mRNA. Analysis of the effect of the respective mutations on the FAH mRNA showed a strong reduction of FAH mRNA levels in association with the nonsense mutations, and normal levels with the missense mutations. The splice consensus mutations give deletions of complete or small parts of exon sequences from the FAH mRNA. Data suggest a founder effect for several of the mutations, with a frequency for both the IVS 6-1 (g-t) and IVS 12 + 5 (g-a) mutations of approximately 30% in the HT 1 probands. No strict correlation between genotype and phenotype, i.e. the acute, subacute or chronic form of HT 1, was evident.

Alleles↗

PubMed2026

Genetic and epigenetic determinants of cytochrome P450 activity in psychopharmacology: from pharmacogenetics to functional pharmacogenomics.

Classical pharmacogenetics has explained interindividual variability in psychotropic drug response primarily through inherited polymorphisms in cytochrome P450 enzymes. This framework successfully identified extreme metabolizer phenotypes and informed genotype-guided dosing recommendations. However, genotype-based predictions frequently correlate more strongly with pharmacokinetic parameters than with clinical outcomes. Patients sharing similar CYP genotypes often exhibit divergent therapeutic trajectories, while metabolic phenotypes may change during treatment without corresponding alterations in DNA sequence. These observations suggest the existence of a genotype-phenotype gap mediated by regulatory processes not captured by genotyping alone. Evidence from epigenetic regulation, environmental modulation of pharmacogene expression, and phenoconversion indicates that metabolic capacity is better understood as a dynamic functional state rather than a fixed inherited trait. This review examines the role of these mechanisms in psychiatric pharmacotherapy and explores the implications of shifting the predictive focus of precision medicine from static genotype to functional state.

Humans↗

PubMed1993

Correlation between genotype and phenotype in patients with cystic fibrosis.

BACKGROUND: Cystic fibrosis is the most common lethal autosomal recessive disorder among whites. Seventy-two percent of patients with this disease are homozygotes or compound heterozygotes for eight mutations of the cystic fibrosis transmembrane conductance regulator gene on chromosome 7: delta F508, G542X, R553X, W1282X, N1303K, 621 + 1G-->T, 1717-1G-->A, and R117H. We studied the relation between genotype and phenotype in patients from 14 countries. METHODS: Each of 399 patients who were compound heterozygotes for delta F508 and one other mutation was matched with the delta F508 homozygote of the same sex who was the closest in age from the same center. A paired analysis was performed of the following outcome variables: age at diagnosis, sweat chloride concentration, growth percentiles, pulmonary-function values, chest-film score, pseudomonas colonization, nasal polyps, pancreatic sufficiency, pancreatitis, diabetes mellitus, meconium ileus, distal intestinal obstruction syndrome, rectal prolapse, cirrhosis, and gallbladder disease. RESULTS: The compound heterozygotes having the genotype R117H/delta F508 clearly differed from the age- and sex-matched delta F508 homozygotes: they more often had pancreatic sufficiency (87 percent vs. 4 percent, P < 0.001), were older when the diagnosis was first made (mean [+/- SD] age, 10.2 +/- 10.5 vs. 2.5 +/- 4.3 years; P = 0.002), and had lower sweat chloride concentrations (80 +/- 18 vs. 108 +/- 14 mmol per liter, P < 0.001). There were no statistically significant differences between delta F508 homozygotes and other compound heterozygotes with regard to any variable tested. CONCLUSIONS: Prenatal and prognostic counseling for patients with the R117H/delta F508 genotype should include the likelihood that they will have long-term pancreatic sufficiency. Patients with the other genotypes should expect the early onset of pancreatic insufficiency. For none of the genotypes studied can predictions be made about the occurrence of common complications or the severity or course of pulmonary disease.

Adolescent↗