Familial Psychosis Associated With a Missense Mutation at MACF1 Gene Combined With the Rare Duplications DUP3p26.3 and DUP16q23.3, Affecting the CNTN6 and CDH13 Genes.

Psychosis is a highly heritable and heterogeneous psychiatric condition. Its genetic architecture is thought to be the result of the joint effect of common and rare variants. Families with high prevalence are an interesting approach to shed light on the rare variant's contribution without the need of collecting large cohorts. To unravel the genomic architecture of a family enriched for psychosis, with four affected individuals, we applied a system genomic approach based on karyotyping, genotyping by whole-exome sequencing to search for rare single nucleotide variants (SNVs) and SNP array to search for copy-number variants (CNVs). We identified a rare non-synonymous variant, g.39914279 C > G, in the MACF1 gene, segregating with psychosis. Rare variants in the MACF1 gene have been previously detected in SCZ patients. Besides, two rare CNVs, DUP3p26.3 and DUP16q23.3, were also identified in the family affecting relevant genes (CNTN6 and CDH13, respectively). We hypothesize that the co-segregation of these duplications with the rare variant g.39914279 C > G of MACF1 gene precipitated with schizophrenia and schizoaffective disorder.

Non-synonymous polymorphism in the neuropeptide S precursor gene and sleep apnea.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is a complex disease with a strong genetic basis. One of the primary molecular domains affected by OSAS is sympathetic activity. Neuropeptide S (NPS) plays an important role in the regulation of the sleep-wakefulness cycle, anxiety states, and daytime sleepiness. It is important to study neuropeptides related to sympathetic activity regulation and how their function could be modified by genetic variants affecting the expression of these molecules. OBJECTIVES: We investigated the association of the non-synonymous polymorphism rs4751440 in the NPS precursor gene with OSAS and certain variables related to OSAS (daytime sleepiness, body mass index (BMI), insulin resistance, and blood pressure). This polymorphism causes an amino acid substitution in exon 3 of the human NPS precursor gene. PATIENTS AND METHODS: We included 253 OSAS patients and 70 healthy subjects. Genotyping was done by polymerase chain reaction using specific flanking primers and agarose gel electrophoresis. Daytime sleepiness, BMI, plasma levels of high-density lipoprotein, glucose, total cholesterol, insulin, triglycerides, and the homeostasis model assessment index were also determined. RESULTS: A similar genotypic and allelic distribution was found in OSAS patients and controls. The risk of OSAS was not associated with the rs4751440 polymorphism. There was no significant interaction between daytime sleepiness or metabolic variables and the rs4751440 polymorphism. CONCLUSION: Genotypic and allelic frequency distribution of the rs4751440 polymorphism was similar in OSAS patients and controls. In this population-based study, we could not show a significant association between rs4751440 polymorphism and susceptibility to OSAS or certain phenotypes related to OSAS (daytime sleepiness, BMI, systolic blood pressure, and insulin resistance) with the exception of diastolic blood pressure.

Genotypic and phenotypic resistance patterns in early-stage HIV-1-infected patients failing initial therapy with stavudine, didanosine and nevirapine.

The objectives of this study were to determine the genotypic and phenotypic patterns of resistance in a group of early-stage antiretroviral-naive patients failing initial therapy with didanosine, stavudine and nevirapine. These patterns of resistance were determined at baseline and at time of virological failure in 89 antiretroviral-naive patients with CD4 cells >500 cells/ml and viral load >5000 copies/ml who received initial antiretroviral therapy with didanosine plus stavudine and nevirapine as part of the SCAN study, and who failed after having reached undetectable plasma levels (<200 copies/ml). Of the 89 patients recruited in the SCAN study, 14 (16%) developed a virological failure after reaching a viral load below 200 copies/ml after a median of 20 months of follow-up. At baseline, none of these 14 patients had genotypic resistance. At time of failure, six out of 14 (43%) failing patients had wild-type genotype and no phenotypic resistance. Suboptimal compliance could be documented in four of these six patients. Seven patients (50%) had nevirapine resistance mutations (mainly K103N [4/7], Y181C/I [2/7], G190A/S [2/7] and V108I [1/7]) associated with phenotypic high-level resistance to nevirapine, delavirdine and efavirenz (nevirapine >47.4- to 58.1-fold, delavirdine >74.4- to 168.9-fold and efavirenz >56.0- to 347.2-fold). Four of these seven patients also had thymidine analogue-associated mutations (TAM) (T215Y/F [2/4], M41L [1/4], D67N [2/4] and K70R [1/4]). Finally, one patient (7%) had exclusively TAM mutations (M41L). None of the patients developed mutations associated with didanosine resistance or phenotypic resistance to didanosine or stavudine. Suboptimal compliance or selection of nevirapine resistance often with TAM mutations was frequently associated with virological failure in a cohort of early-stage chronic HIV-1-infected patients treated with a protease inhibitor-sparing regimen.