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Biomedical subjects

L Fañanás

Publications and source records attributed to L Fañanás.

At least 19 recordsLinked to original sources
PubMed2004

Dermatoglyphic profile in 22q deletion syndrome.

A genetic subtype of schizophrenia has been described in 22q11 Deletion syndrome. Previous studies have described an excess of dermatoglyphic alterations in schizophrenia, such as low a-b ridge counts (ABRCs), a high frequency of ridge dissociations, and increased dermatoglyphic fluctuating asymmetry. Little is known however, about the dermatoglyphic profile of 22qDS subjects showing psychotic symptoms and its similarity to the previously reported anomalies in schizophrenia. We studied the palmar dermatoglyphics of 22 subjects with 22qDS of predominantly Caucasian origin, 15 of whom had psychotic illness, and in 84 healthy controls of similar ethnicity. We observed higher values for total ATD angle in cases than in controls (P = 0.04). In addition, there was an excess of radial figures in the hypothenar area in cases, especially in the left hand. Interestingly, greater fluctuating asymmetry, determined by the absolute difference between right and left ABRC, was observed in 22qDS subjects compared to controls (P = 0.05). However, no differences were found for ABRCs and frequency of dissociations. Despite the small sample size, the palmprints analyzed suggest the existence of an altered dermatoglyphic profile in 22qDS, involving: (i) ATD angle amplitude, (ii) presence of radial loops in the hypothenar area, and (iii) an increment of fluctuating asymmetry. The first two features are similar to those found in other genetic syndromes associated with low IQ, while high levels of fluctuating asymmetry have often been reported in schizophrenia.

Adolescent↗
PubMed2002

[Genetic foundations of vulnerability to depression].

Depression is a complex phenotype probably heterogeneous in its biology and in its aetiology. Genetic studies have contributed to clarifying some aspects of that heterogeneity, but we are still far from being able to establish its molecular foundations, although a certain degree of genetic variability in genes of the serotoninergic system appear to contribute to the risk of the disease and to certain of its clinical aspects. The risk of a major depressive episode increases in relation to the number of genes shared with an affected person but, in genetic terms and given the differential risks found, there is also a certain overlap with bipolar disorder and schizophrenia. These data lead to reflection on the meaning of genetic risk detected in families and its specificity. Perhaps genetic studies will have to leave the categorical definition of phenotypes and begin to use the dimensions of psychopathology for delimiting the biological and genetic subgroups present in functional psychoses.

English Abstract↗
PubMed2001

The 5-HT(2A) receptor gene 102T/C polymorphism is associated with suicidal behavior in depressed patients.

Several lines of evidence suggest that genetic factors constitute an important determinant of suicidal behavior. A significant association between the 5-HT(2A)-C allele and suicidality has recently been reported. The aim of this study was to investigate whether the proposed association between 5-HT(2A)-102T/C polymorphism and suicidality could be replicated in a larger and independent sample of Spanish patients with major depression. The 102T/C polymorphism of the 5-HT(2A) receptor gene was analyzed in 159 patients with major depression (DSM-IV criteria) and 164 unrelated and healthy controls using a case control design. All individuals were subjects of Spanish origin. Significant differences in allele (chi-square = 4.13, df = 1, P = 0.04) and genotype (chi-square = 6.19, df = 2, P = 0.04) distributions were found between non-suicide attempters and suicide attempters. Moreover, those patients carrying 5-HT(2A)-C allele had more than five times the risk for attempting suicide than noncarriers (OR = 5.50, 95% CI = 1.18-35.20, P = 0.01). Our results replicate the proposed association between 5HT(2A)-C allele and suicidality in major depression. Moreover, no overall associations are detected when patients with major depression and controls are compared for 102T/C frequencies, suggesting that the increased risk for suicidality conferred by 5-HT(2A)-C allele is primarily associated with suicidal behavior and not with the diagnosis of major depression itself.

Adult↗
PubMed2001

Association study between novel promoter variants at the 5-HT2C receptor gene and human patients with bipolar affective disorder.

Two recently described adjacent DNA polymorphisms [(GT)12-18 and (CT)4-5] in the 5'-regulatory region of 5-HT2C receptor gene were analysed in a sample of 88 bipolar patients and 162 controls, all of Spanish origin. Statistical analyses revealed no overall allele or genotype associations with the disease. A haplotype analyses between the (GT)12-18/(CT)4-5 motif and a Cys23Ser variant of the 5-HT2C gene (which had previously been genotyped in the same sample) showed similar distributions between cases and controls. Only a slight increase of s-Ser23 haplotype was found in the subgroup of bipolar women with family history of psychiatric illness (OR=1.24 [95%CI: 1.12-1.38]).

Bipolar Disorder↗
PubMed2001

Genetic variation in the 5-HT5A receptor gene in patients with bipolar disorder and major depression.

In the present study, genetic variation of the 5-HT5A receptor was analyzed in patients affected by affective disorders and healthy controls. The sample consisted of 181 patients with major depression, 88 patients with bipolar affective disorder (BP) and 157 unrelated controls (C), all of Spanish origin. Two polymorphisms (-19G/C and 12A/T) in the 5-HT5A receptor gene were analyzed by polymerase chain reaction amplification and subsequent enzyme digestion. No genotype, allele or haplotype differences were found when we compared patients and controls. When clinical variables were considered as possible tools for detecting genetic heterogeneity, no differences were found. Our results suggest that the polymorphisms analyzed in the 5-HT5A receptor gene do not play a major role in the pathogenesis of affective disorders.

Adult↗
PubMed2001

Variability in the 5-HT(2A) receptor gene is associated with seasonal pattern in major depression.

The 102-T/C polymorphism of the 5-HT(2A) receptor gene was analysed in 159 patients with major depression and 164 unrelated and healthy controls using a case-control design. Allele and genotype frequencies did not differ between cases and controls. No differences according to sex, age of onset, melancholia, suicidal behaviour or family history of psychiatric illness were found. However, genotype distributions significantly differed between patients with seasonal pattern in their episodes (MDS) and patients with no seasonal pattern (N-MDS) (chi(2) = 10.63; P = 0.004). A seasonal pattern was 7.57 times more frequent in 102C-allele carriers than in 102T homozygous (95.1% of patients MDS carried 102C-allele vs 72% of patients N-MDS (chi(2) = 9.45, df=1, P = 0.002; OR = 7.57 (95% CI: 1.65--48.08)). These results suggest that variation in the 5-HT2A receptor gene may play a role in the development of major depression with seasonal pattern and support the existence of a genetic and etiological heterogeneity underlying the diagnosis of major depression.

Case-Control Studies↗
PubMed2001

Dermatoglyphics and abnormal palmar flexion creases as markers of early prenatal stress in children with idiopathic intellectual disability.

A number of studies have shown the importance of dermatoglyphics as markers of prenatal disturbance in developmental disorders of unknown origin. Genetic and non-genetic factors are involved in the aetiology of intellectual disability (ID), although the cause remains unknown in up to 50% of cases. The aim of the present study was to analyse dermatoglyphic traits and abnormal palmar flexion creases as markers of environmental prenatal stress in children with idiopathic ID (IID) using a case-control study design. Three dermatoglyphic variables, which have been reported as altered in other congenital disorders, were considered were studied in a sample of 62 children with IID (IQ < 70) and 75 healthy controls (IQ > 70): (1) fingerprint patterns; (2) total a-b ridge count (TABRC); and (3) abnormal palmar flexion creases (APFCs). More arches, the simplest fingerprint pattern, and more radial loops, an unusual pattern, were found in IID cases in comparison to controls (chi23 = 9.26; P = 0.02), with especially marked differences in boys (chi23 = 6.5; P = 0.0008). A significant increase of APFCs was also found in the affected children (chi24 = 28.52; P < 0.00; odds ration = 3.86, 95% confidence interval = 1.77-8.47). For TABRC, the differences between IID cases and controls failed to reach the conventional level of significance. These findings suggest that environmental factors acting early in development, or mechanisms involving an interaction of genotype and environment could be involved in the aetiology of some cases of ID.

Adolescent↗
PubMed2000

Developmental instability and schizotypy.

INTRODUCTION: It has been suggested that evidence of developmental disturbance of cognition and lateralisation in schizophrenia can be best understood from the perspective of developmental stability (DS), an indicator of the extent to which an individual develops according to a specified ontogenic programme in the presence of environmental noise. Higher levels of fluctuating asymmetry (FA; the difference between right and left side of a quantitative morphological trait such as dermatoglyphics) are thought to reflect less DS. We examined this issue for dimensions of schizotypy. METHODS: Associations between FA, measures of laterality and cognitive function on the one hand, and negative and positive dimensions of schizotypy on the other, were examined in a sample of 260 healthy adolescents aged 11.9-15.6years. FA was measured as a-b ridge count right-left differences. Neuropsychological measures yielded a general cognitive ability score and a frontal function score. Laterality was assessed with the Annett scale. RESULTS: Measures of psychosis proneness were normally distributed. Negative schizotypy was associated with more FA and lower general cognitive ability in a dose-response fashion. The association with FA was more apparent in boys. No associations existed with laterality or frontal function. CONCLUSION: The negative dimension of schizotypy may be associated with early developmental instability, resembling the pattern seen in the negative symptom dimension of schizophrenia. Measures of fluctuating asymmetry may be more sensitive with regard to the schizotypy phenotype than measures of laterality.

Adolescent↗
PubMed2000

Increased morbid risk for schizophrenia in families of in-patients with bipolar illness.

BACKGROUND: It has been reported that relatives of probands with severe, psychotic forms of bipolar illness have increased rates of schizophrenia but not the relatives of individuals with milder, non-psychotic forms of disorder. In this study, we examined the prevalence of psychiatric disorders in the first degree relatives of a sample of 103 inpatients with bipolar disorder and in a matched control sample of 84 healthy individuals. METHOD: Relatives of cases and controls were interviewed using the FH-RDC to determine familial morbid risk for schizophrenia and bipolar disorder. Age- and sex-adjusted morbidity risks were calculated in both samples according to the method of Strömgren. RESULTS: The morbid risks for both bipolar disorder (4.9%) and schizophrenia (2.8%) were higher in relatives of patients than in relatives of controls (0.3% and 0.6% respectively). The relative risks were 14.2 [95% confidence interval (CI)=3.1-64.2] for bipolar disorder and 4.9 (95% CI=1.3-18.8) for schizophrenia. Relatives of women with early onset of bipolar illness had the highest morbid risks for both bipolar illness and schizophrenia. The presence of more than one patient with bipolar disorder in a family increased the risk for schizophrenia nearly fourfold (RR=3.5, 95% CI=1.2-10.2). There was no additional effect of presence of psychotic features. CONCLUSION: Our results suggest that the transmission of psychosis is not disorder-specific. Bipolar illness characterised by a high familial loading is associated with increased risk of schizophrenia in the relatives.

Adolescent↗
PubMed2000

Georgian and kurd mtDNA sequence analysis shows a lack of correlation between languages and female genetic lineages.

Mitochondrial DNA sequences from Georgians and Kurds were analyzed in order to test the possible correlation between female lineages and languages in these two neighboring West Eurasian groups. Mitochondrial sequence pools in both populations are very similar despite their different linguistic and prehistoric backgrounds. Both populations present mtDNA lineages that clearly belong to the European gene pool, as shown by 1) similar nucleotide and sequence diversities; 2) a large number of sequences shared with the rest of European samples; 3) nonsignificant genetic distances; and 4) classification of the present lineages into the major European mtDNA haplogroups already described. The outlier position of the populations from the Caucasus according to classical genetic markers is not recognized in the present Georgian mtDNA sequence pool. This result suggests that the differentiation of mtDNA sequences in West Eurasia and the outlier features of Caucasian populations should be attributed to different processes. Moreover, the putative linguistic relationship between Caucasian groups and the Basques, another outlier population within Europe for classical genetic markers, is not detected by the analysis of mtDNA sequences.

Adult↗
PubMed1998

Congenital dermatoglyphic malformations in severe bipolar disorder.

Dermatoglyphic alterations may be the result of early prenatal disturbances thought to be implicated in the aetiology of psychiatric illness. In order to test this hypothesis in the particular case of bipolar disorder, we assessed two congenital dermatoglyphic malformations (ridge dissociation (RD) and abnormal features (AF)) and two metric dermatoglyphic traits (total finger ridge count (TFRC) and total a-b ridge count (TABRC)) in a sample of 118 patients with chronic DSM-III-R bipolar illness, and 216 healthy controls. Bipolar cases showed a significant excess of RD and AF (OR = 2.80; 95% CI: 2.31-3.38) when compared with controls. In the cases, the presence of anomalies was associated with earlier age of onset. No differences were found for TFRC and TABRC. No associations were found with sex or familial morbid risk of psychiatric disorders. Our findings add further weight to the suggestion that early developmental disruption is a risk factor for later bipolar disorder.

Bipolar Disorder↗
PubMed1998

Variability in the serotonin transporter gene and increased risk for major depression with melancholia.

The serotonin transporter (SERT) gene is a particularly interesting candidate for genetic involvement in affective disorders owing to its role in both the regulation of serotonergic neurotransmission and the mechanism of action of many antidepressant drugs. In this study, variability in the SERT gene was analyzed for the first time in a sample of patients with major depression with melancholia (MDDM) in the context of a genetic association study. Two different polymorphisms of the SERT gene (17q11.1-17q12) were analyzed: a variable number of tandem repeats (VNTR) polymorphism in intron 2, and a deletion/insertion polymorphism (5-HTTLPR) in the promoter region of the gene, the short variant of which (allele 484) reduces the transcriptional efficiency of the SERT gene. Our sample consisted of 74 unrelated subjects who strictly met DSM-IV criteria for MDDM and 84 healthy controls, all of Spanish origin. The analysis of haplotype distribution for both polymorphisms showed significant differences between cases and controls (log-likelihood ratio chi2=11.15, df=4, P=0.025). Moreover, when the frequencies of the 484-STin2.10 haplotype were considered in comparison with any other haplotype combination, a significant increase in this haplotype was found in patients with MDDM [z=2.53 (95% CI, 1.21-5.34), P=0.007]. According to these results, variability in the SERT gene has a small effect on liability to MDDM. Our findings are compatible with an additive effect of both the 484 low-activity allele and a mutation elsewhere within the transporter gene or a susceptibility locus nearby in linkage disequilibrium with the VNTR marker.

Carrier Proteins↗
PubMed1997

Genetic variation of the 5-HT2A receptor gene and bipolar affective disorder.

Abnormalities of the serotonergic system have classically been associated with the origin of affective disorders through the biochemical action of therapeutic agents and their role in affective and perceptual states. In the present study, we hypothesized that genetic variation in the 5-hydroxytryptamine (serotonin) type 2A (5-HT2A) receptor gene (HTR2A) might have an effect on the aetiology of bipolar affective disorder. Four different polymorphisms in the HTR2A gene were studied in 88 patients with bipolar affective disorder and 113 healthy controls, all of Spanish origin. No significant association was observed between any of the four polymorphisms at the HTR2A locus, whether tested individually or as haplotypes, and bipolar affective disorder. The lack of association suggests that HTR2A is not a major risk factor for bipolar affective disorder.

Bipolar Disorder↗
PubMed1997

Association analysis of the catechol O-methyltransferase gene and bipolar affective disorder.

OBJECTIVE: Catechol O-methyltransferase (COMT) is an enzyme that inactivates catecholamines. Two common COMT alleles determine high and low activity of the enzyme. Previous studies using biochemical methods found lower enzyme activity in patients with major depression and bipolar disorder in comparison with control values, suggesting that a dysfunction in catecholamine metabolism may be related to the etiology of depression. METHOD: The authors studied two recently described DNA polymorphisms at the COMT gene (a silent C256G mutation and a structural mutation, Val-108-Met) in 88 patients with bipolar disorder and in 113 healthy comparison subjects, all of Spanish origin. RESULTS: The frequency of the C256 allele was 0.58 in the patients and 0.54 in the comparison subjects. The frequency of the Val108 variant was 0.57 for both the patients and the comparison subjects. No allelic or genotypic associations were observed. CONCLUSIONS: The lack of association suggests that the COMT gene is not a major risk factor for bipolar disorder.

Alleles↗