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At least 217 records · Page 12Linked to original sources

PubMed2004

[Criswick-Schepens syndrome -- familial exudative vitreoretinopathy. Report of six cases in two consanguineous families].

BACKGROUND: Familial exudative vitreoretinopathy is a hereditary, bilaterally progressive formation of a vitreoretinal membrane. It usually occurs in full-term newborns without previous treatment with hyperbaric oxygen. In this report, we present six cases of this disease with various abnormalities of the posterior segment diagnosed in two Syrian families related by first degree of consanguinity. DESIGN: A retrospective family analysis and presentation of cases. CASE PRESENTATION: Six members of the two consanguineous families, aged between 3.5 and 13 years, who were systemically healthy, presented with a visual acuity ranging between light perception and 0.4 with bilateral fundus changes. The findings included: papillary, macular, and retinal temporal traction in 11 eyes, a retinal fold in 7 eyes, a fibrovascular mass in 11 eyes, vitreoretinal traction in 5 eyes, subretinal exudation in 2 eyes, pigmentary abnormalities in 2 eyes, temporal or total tractional retinal detachment in 2 eyes, and vitreous hemorrhage in 1 eye. SUMMARY: Familial exudative vitreoretinopathy is characterized by fundus changes that resemble retinopathy of prematurity and must be differentiated from other diseases (e.g., Coats' disease, incontinentia pigmenti, persistent hyperplastic primary vitreous, and Norrie's disease).

Adolescent↗

PubMed2006

Phenotype of three consanguineous Tunisian families with early-onset retinal degeneration caused by an R91W homozygous mutation in the RPE65 gene.

PURPOSE: To identify the genetic defect, and to phenotype, three consanguineous Tunisian families presenting with early-onset retinal degeneration (EORD). METHODS: All accessible family members were included. They underwent blood sampling and ophthalmological examination including, when possible, full-field ERG and pupillometry. A genome-wide linkage analysis was initiated. Mutation analysis of the RPE65 gene within the linked interval was performed by bi-directional sequencing. RESULTS: Eleven out of 53 examined members were clinically affected with an EORD. Linkage analysis revealed a maximal lod score of 4.02 (theta=0.1) for the marker D1S207 on 1p31. Mutational screening of the RPE65 gene identified a homozygous R91W mutation co-segregating with the disease in all affected individuals. Eleven homozygotes had nystagmus and acuities ranging from CF to NLP. Two retinal patterns were identified: pattern 1 presented mid-peripheral deep white dot deposits and virtually no clumped pigmentation, whereas pattern 2 showed mid-peripheral pigmented clumps without any white deposits. Homozygotes had no detectable full-field ERG and an abnormal pupillary light reflex. Eleven heterozygotes had normal visual function. CONCLUSION: We identified and characterised an endemic form of early onset rod-cone dystrophy in a consanguineous population from northeastern Tunisia, due to the prevalence of a single RPE65 mutation. Two funduscopic patterns were identified: white dot deposits in earlier stages and clumped pigment in later stages.

Adult↗

PubMed2006

DNA-based diagnosis of malignant osteopetrosis by whole-genome scan using a single-nucleotide polymorphism microarray: standardization of molecular investigations of genetic diseases due to consanguinity.

Malignant osteopetrosis, a severe disease causing early infantile death in humans, is caused by mutations in the TCIRG1, CLCN7, or OSTM1 genes. We have established the molecular basis of malignant osteopetrosis in a Chinese family by means of whole-genome scans based on high-density single-nucleotide polymorphism (SNP) microarrays. Because the parents were consanguineous, the disease-causing locus should be located in an autozygous chromosomal region. Mapping revealed that among the three possible causal loci, only the CLCN7 gene was located in an autozygous region. Mutational analysis of the CLCN7 gene showed that the proband was homozygous for a novel missense mutation, p.I261F. p.I261 is located in helix F of the chloride channel, near a critical site for gating of the channel. This mapping study prepares the ground for future mutation studies by decreasing the burden of completely sequencing all possible loci for this disease. This approach can be used to standardize molecular investigations of genetic diseases due to consanguinity to a whole-genome scan and subsequent sequencing of the mapped disease gene.

Asian People↗

PubMedDate not supplied

Laboratory evidence of unsuspected parental consanguinity among cases of disputed paternity.

A search was conducted to find evidence of possible incestuous unions between the biologic parents of children involved in 2500 paternity cases. Suspicion was raised when either (1) a mother and her child possessed identical HLA phenotypes, or (2) the child appeared to be possibly homozygous for one maternal haplotype (i.e., one of the child's HLA haplotypes was a blank). These mother-child HLA-haplotype dualisms (MHDs) occurred in 5% of all cases. Frequency of exclusion of the accused men in cases demonstrating MHD, was compared with the remaining paternity cases. No significant difference was found in overall exclusion rates between MHD cases and controls when exclusion produced by HLA and red cell antigen systems were observed. However, there was a greater rate of exclusion in MHD cases when comparing exclusions produced by red cell antigen systems regardless of whether HLA tests excluded paternity (p less than 0.025). MHD cases involving teenaged mothers differed from control cases in frequency of exclusion of paternity only on the basis of red cell antigen phenotyping (p less than 0.005). The HLA system's usefulness in paternity testing is diminished when there is MHD; multiple, independently-inherited systems are relatively more useful in these circumstances. The search method detects only half of potential incest cases; proof of incest requires more extensive testing for homozygosity among other polymorphisms. Since calculations of likelihood of paternity are inappropriate in cases involving close consanguinity, detection and follow up studies are important. Data suggest that one-fifth of MHD cases may involve first degree consanguinity and that the incest rate among paternity cases may be as high as 2%.

Alleles↗

PubMedDate not supplied

Awareness of folic acid for prevention of neural tube defects in a community with high prevalence of consanguineous marriages.

Neural tube defects (NTDs) are severe congenital malformations and can be fatal. Intake of 0.4 mg folic in the periconceptional period reduces the risk of NTD by 50-70%. Consanguinity in the Arab population in Israel is a prevalent custom. The aim of this study was to assess the level of awareness regarding folic acid and its effect in the prevention of NTD among Arab Israeli women of childbearing age. We conducted a cross-sectional study. Of the 653 women (18-45 years) who were randomly selected for interview while visiting their family physician or well-baby clinic, 624 women completed the questionnaire. Fifty-three percent (n = 333) of the respondents had heard of folic acid; 14% (n = 89) were familiar with the protective effect of NTD and 3% (n = 18) had taken folic acid in the first months of pregnancy whereas none of them had used it in the preconception period. Highly educated women, women with one or two children, paramedics, and women of high socioeconomic status were more knowledgeable about the protective effects of folic acid (P < 0.001). Age and religion had no significant effect. An urgent need exists to improve the awareness of this population to the protective effect of folic acid. Daily supplementation and fertification of food with folic acid should be considered as the best way to improve the balance of folic acid in women of childbearing age of this special population (high prevalence of consanguinity).

Adolescent↗

PubMed2005

Case report of a rare syndrome associating amelogenesis imperfecta and nephrocalcinosis in a consanguineous family.

A rare syndrome associating amelogenesis imperfecta (AI) with nephrocalcinosis has been reported. The purpose of this study is to characterise the phenotype of a consanguineous family presenting amelogenesis imperfecta, delayed permanent teeth eruption and nephrocalcinosis. Six family members were examined. Ground sections of the case index deciduous teeth and biopsies of enlarged dental follicles were analysed. The patients's parents were first cousins. The case index had yellow discoloration and altered teeth shapes, retention of deciduous teeth, and delayed eruption. Panoramic radiographs revealed multiple enlarged pericoronal follicles in unerupted teeth and generalised intrapulpal calcifications. Renal ultrasound showed the presence of nephrocalcinosis. No other family members presented enamel defects or nephrocalcinosis. Histologically, the enamel appeared hypoplastic, and dental follicles indicated pericoronal hamartoma. The consanguineous marriage suggests an autosomal recessive mode of inheritance. Further studies are necessary to clarify the genetic defect behind this syndrome that associates AI, nephrocalcinosis and impaired tooth eruption.

Adolescent↗

PubMed2004

Sperm tail agenesis in a case of consanguinity.

OBJECTIVE: To report a case of 100% teratozoospermia in a patient whose family history presented a high degree of consanguinity. DESIGN: Case report. SETTING: University-based andrology clinic. PATIENT(S): A 27-year-old man undergoing infertility evaluation. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Serum hormone analysis, standard (World Health Organization) semen quality evaluation, sperm ultrastructure, lymphocytic karyotype, and polymerase chain reaction screening for Y chromosome microdeletions in peripheral blood. RESULT(S): One hundred percent teratozoospermia characterized by shape alterations of the heads and tail agenesis on standard morphology evaluation, which was confirmed using electron microscopy. CONCLUSION(S): A case of familial infertility in a consanguineous patient characterized by morphological abnormalities of spermatozoa such as tail agenesis, chromatin subcondensation, and residual cytoplasmic droplets.

Adult↗

PubMed2006

New fibrous sheath anomaly in spermatozoa of men with consanguinity.

OBJECTIVE: The cause of the sperm motility impairment was investigated in infertile men. DESIGN: Case report. SETTING: University-based andrology laboratory. PATIENTS: Two unrelated consanguineous patients. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The sperm flagella lengths were measured using quantitative analysis software and their ultrastructural anomalies were quantitatively recorded. RESULT(S): A total of 67.5% of the flagella were truncated, and 100% lacked the medium region of the ribs of the fibrous sheath. CONCLUSION(S): The data suggested a morphogenetic anomaly at the stage where rib precursors are formed during spermiogenesis. The consanguinity of these patients suggested a genetic origin for this newly discovered anomaly of the human sperm's fibrous sheath. The family tree appears to indicate an autosomal recessive inheritance.

Adult↗

PubMed2006

Homozygosity mapping as a screening tool for the molecular diagnosis of hereditary skin diseases in consanguineous populations.

BACKGROUND: The routine diagnosis of genodermatoses is significantly complicated by the fact that in this group of disorders, clinical manifestations may result from mutations in unrelated genes (genetic heterogeneity) and mutations in the same gene often lead to dissimilar clinical signs (phenotypic heterogeneity). METHODS: In this study, we applied the principles of homozygosity mapping as a screening method before formal mutational analysis in an attempt to facilitate the molecular diagnosis of genodermatoses in consanguineous families. The method was evaluated in a retrospective fashion in 4 families previously assessed with junctional epidermolysis bullosa and in a prospective manner in 11 families with congenital recessive ichthyosis. RESULTS: The method was found to be efficient in directing the molecular analysis to one of the 4 genes commonly involved in the pathogenesis of junctional epidermolysis bullosa or in identifying cases of congenital recessive ichthyosis caused by mutations in TGM1. We found that this diagnostic strategy results in a 5-fold decrease in the cost of mutation analysis. LIMITATIONS: The proposed diagnostic strategy is applicable to consanguineous families only and, therefore, cannot be used in outbred populations. CONCLUSION: Our results indicate that homozygosity mapping may serve as a useful adjunct in the molecular diagnosis of junctional epidermolysis bullosa or congenital recessive ichthyosis in inbred populations. This study emphasizes the usefulness in human genetics of diagnostic strategies tailored to the demographic features of target populations.

Base Sequence↗

PubMed2006

Genetic heterogeneity within a consanguineous family involving the LGMD 2D and the LGMD 2C genes.

The sarcoglycanopathies are a group of autosomal recessive limb girdle muscular dystrophies (AR-LGMD 2) characterised by mutations in gene encoding one of the sarcoglycan subunits. Mutations in SGCA, SGCB, SGCG and SGCD genes are associated with LGMD 2D, 2E, 2C and 2F, respectively. We report three Tunisian patients belonging to the same consanguineous family sharing similar LGMD 2 phenotype but heterogeneous sarcoglycans immunohistochemical patterns. Linkage analysis suggests linkage with the LGMD 2D locus for the two siblings and with LGMD 2C locus for the third patient. Mutation analysis revealed two distinct mutations. A del521T homozygous mutation in exon 6 of the SGCG gene (LGMD 2C), widely distributed in Tunisian patients, was found in one patient, whereas a 157G>A homozygous mutation in exon 2 of the SGCA gene (LGMD 2D) was found in the two siblings. The presence of two distinct genetic forms, LGMD 2C and LGMD 2D in a consanguineous family raises the problem of the complexity of genetic counselling in inbred populations.

Adult↗

PubMed2003

Consanguineous marriage resulting in homozygous occurrence of X-linked retinoschisis in girls.

PURPOSE: To investigate a family afflicted with X-linked retinoschisis and to determine the pedigree leading to such an occurrence. DESIGN: Observational case series. METHODS: Visual acuities were measured at The Aga Khan University Hospital Ophthalmology clinic. Slit-lamp examination, direct and indirect ophthalmoscopies were performed on each of the seven members of this family. The pedigree was established by appropriate questioning about the rest of their family. RESULTS: The pedigree revealed the homozygosity of the four daughters for the XLRS mutations borne out of the consanguineous marriage between an affected father and a carrier mother. CONCLUSIONS: This is the first report showing that consanguineous marriages lead to homozygous pairing of XLRS genes in female children, as concluded after a MEDLINE search.

Adolescent↗

PubMed1993

Consanguinity in north Jordan: prevalence and pattern.

The rate of consanguineous mating in north Jordan was 63.7% with an average inbreeding coefficient of 0.0283. First cousin marriages were the most predominant type (58.5%); villagers showed higher levels than city dwellers. The level of female education did not influence consanguinity rate.

Adult↗

PubMed1995

Sex linked versus autosomal inbreeding coefficient in close consanguineous marriages in the Basque country and Castile (Spain): genetic implications.

Pedigree structures of 161 uncle/niece-aunt/nephew and 4420 first cousin consanguineous marriages registered during the 19th and 20th centuries in two large and very different Spanish regions have been analysed and their genetic consequences evaluated. The frequencies of the different pedigree subtypes within each degree of relationship were quite similar in both populations despite significant heterogeneity in inbreeding patterns. The mean X-linked inbreeding coefficient (Fx) for each type of cousin mating was calculated and compared to that expected for autosomal genes (F). The effect of genealogical structure on the Fx/F ratio was compared to different cultural populations worldwide. Preferentiality and avoidance of close consanguinity along with specific types of pedigrees are discussed on the basis of premarital migration and sociocultural rules still deeply rooted in certain human groups. By admitting that the observed Fx coefficient is usually higher than F in most human populations some remarks have been made in terms of population genetic risk.

Chromosome Aberrations↗

PubMed2006

Migration as a determinant of marriage pattern: preliminary report on consanguinity among Afghans.

Two sample populations, one refugee and one resident, were studied. The frequencies of consanguineous marriages came out to be 49.8%and 55.4%, respectively, for the refugees and the residents. Caste endogamy was dominant both in the residents and the refugees. The mean coefficient of inbreeding was calculated to be 0.0303 for the refugee population and 0.0332 for the resident population samples. First cousin marriage was the dominant type of marriage in both samples; father's brother's daughter (FBD) marriage was more frequent among the refugees while mother's brother's daughter(MBD) marriage was more frequent among the residents. Education has no decreasing effect on the incidence of consanguineous marriages. A significant difference in the pattern of marriages in the refugees is observed after the Saur Revolution of 1979.

Afghanistan↗

PubMed2006

Cervico-oculo-Acoustic syndrome in a male with consanguineous parents.

BACKGROUND: The cervico-oculo-acoustic syndrome comprises Klippel-Feil anomaly, sensorineural deafness and Duane's retraction syndrome. Polygenic, autosomal dominant, and X-linked inheritance have been hypothesized. The disorder has rarely been reported in males. CASE REPORT: A 42-year-old male, born of consanguineous parents, presented with Duane's syndrome, mixed hearing loss, C2-C3 fusion, neck stiffness, and right facial palsy. A variety of cardiac, neurological and urogenital anomalies occurred in his relatives. The electro-oculographic studies showed impaired abduction and adduction of the right eye and impaired abduction of the left eye. Vergence, vertical eye movements and peripheral vestibular responses were normal. Somatosensory evoked potentials showed absence of the N13 peak and brainstem auditory evoked potentials bilateral delay of the I-III interpeak latencies. CONCLUSIONS: Consanguinity of the patient's parents, not previously reported, suggests autosomal recessive inheritance, but autosomal dominant inheritance is indicated by the family history. The pattern of the oculomotor deficit is consistent with bilateral dysplasia of the abducens nuclei with preserved internuclear neurons in the right abducens nucleus. Neurophysiological investigations revealed lower brainstem and cervical cord involvement.

Abducens Nerve↗

PubMed2004

Refining the DFNB17 interval in consanguineous Indian families.

We previously mapped the DFNB17 locus to a 3-4 cM interval on human chromosome 7q31 in a large consanguineous Indian family with congenital profound sensorineural hearing loss. To further refine this interval, 30 new highly polymorphic markers and 8 SNPs were analyzed against the pedigree. Re-analysis in the original DFNB 17 family and additional data from a second unrelated consanguineous family with congenital deafness found to map to the interval, limited the area of shared homozygosity-by-descent (HBD) to approximately 4 megabase (Mb) between markers D7S2453 and D7S525. Nineteen known genes and over 20 other cDNAs have been identified in the refined DFNB 17 interval, including the SLC26A4 gene. We have analyzed 4 other cochlear-expressed genes that map to the DFNB17 interval as candidate genes. Analysis of coding and splice site regions of these cochlear expressed genes did not reveal any disease causing mutations. Further study of other candidate genes is currently underway.

Chromosome Mapping↗

PubMed2001

Co-existence of lysosomal storage diseases in a consanguineous family.

Lysosomal storage diseases are rare and coexistence of more than one in a family can present a diagnostic challenge as illustrated by this study. The index case born to consanguineous Asian parents presented with developmental delay. Investigations led to an incidental finding of Fabry disease. After numerous additional investigations over a year, a second diagnosis of aspartylglucosaminuria (AGU) was made. A family history of renal disease and developmental delay was disclosed. The sister and first cousin of the index case were diagnosed as homozygous for AGU, but do not have Fabry disease. The younger brother has since been diagnosed with both Fabry disease and AGU. Another cousin has learning difficulties and fits, but is heterozygous for AGU, and possibly has another uncharacterised autosomal recessive disorder. In a family with consanguinity when the clinical picture in an individual is not fully explained by the presence of one rare metabolic disease, it is essential to investigate further for the presence of others.

Acetylglucosamine↗

PubMed1998

The role of consanguinity and inbreeding as a determinant of spontaneous abortion in Karachi, Pakistan.

The effect of consanguinity and inbreeding on spontaneous abortion is assessed with the help of data from a population-based study conducted in four squatter settlements of Karachi, Pakistan. The analysis is based on 4966 pregnancy records belonging to 873 women. Results of the multivariate analysis show that both consanguinity and inbreeding were independent risk factors for spontaneous abortion despite undertaking control for other biological and socio-demographic factors that could confound the association. The combination of fetal and parental inbreeding led to a greater likelihood of a pregnancy ending in spontaneous abortion than one generation of inbreeding alone.

Abortion, Spontaneous↗