RESUMO
BACKGROUND: Duchenne muscular dystrophy (DMD) is the most common muscular dystrophy that affects young boys and the dystrophin gene on the X chromosome has been found to be associated with the disorder. MATERIALS AND METHODS: In this prospective study, 112 clinically diagnosed DMD patients had muscle biopsy and were tested for exon deletions. Genotyping was also carried out at STR44, STR45, STR49 and STR 50 markers in 15 families. RESULTS: Of the 112 clinically suspected DMD patients, the diagnosis of DMD was confirmed by histopathology and/or genetics in 101 patients. The mean age of onset was 3.1+/-1.44 years (1-6 years) and the mean age at presentation was 8.0+/-3.1 years (1.1-18.0 years). Delayed motor milestones were present in 63 (62.3%) patients. The mean creatine kinase value was 11822.64+/-8206.90 U/L (1240-57,700). Eighty-four patients had muscle biopsy and immunohistochemistry was done in 60 muscle samples, all of which demonstrated absence of dystrophin staining. Of the 60 dystrophin-negative cases, 73% showed deletion of at least one exon. Single exon deletion was found in 20.4%. Distal hotspot Exons 45, 47, 49 and 50 were the commonly deleted xenons and the deletion rates were 36%, 35%, 33.7% and 38.5% respectively. CONCLUSIONS: In this study population in south India the deletion rate was 73% and were more frequent in the distal end exon. With the availability of genetic analysis, the first investigation of choice in DMD should be genetic studies and muscle biopsy should be considered only if the genetic tests are negative or not available.
Assuntos
Distrofina/genética , Repetições de Microssatélites/genética , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/patologia , Deleção de Sequência/genética , Criança , Creatina Quinase/sangue , Análise Mutacional de DNA , Distrofina/metabolismo , Éxons/genética , Saúde da Família , Feminino , Genótipo , Humanos , Índia/epidemiologia , Masculino , Relações Mãe-Filho , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Distrofia Muscular de Duchenne/sangue , Estudos Prospectivos , Sarcoglicanas/metabolismoRESUMO
A six year old boy presented with classical features of Duchenne Muscular Dystrophy (DMD) and was confirmed by absent dystrophin staining on muscle biopsy. In the paternal line there were 5 affected individuals across two generations with classical DMD. There was no family history of the illness in the maternal line. Molecular genetics analysis by PCR of the exons showed a deletion in exon 45 in two affected individuals. Microsatellite analysis showed that though the deletion was observed in the same locus in exon 45 it is a new independent mutation.
Assuntos
Distrofina/genética , Repetições de Microssatélites/genética , Distrofia Muscular de Duchenne/genética , Linhagem , Deleção de Sequência/genética , Criança , Análise Mutacional de DNA , Éxons/genética , Humanos , Índia , Masculino , Músculo Esquelético/patologia , Distrofia Muscular de Duchenne/patologiaRESUMO
BACKGROUND: Altered serotonergic function is implicated in the aetiology and pathogenesis of a host of psychiatric disorders, and structural variations/polymorphisms in genes encoding the serotonin transporter and various serotonin receptor subtypes are attractive candidates to investigate the biological component underlying these disorders. Specific phenotypic subtypes, that perhaps represent homogeneous forms of the disorder, may increase the power to detect genes in complex diseases. OBJECTIVE: We investigated regulatory and functional polymorphic DNA markers of serotonergic candidate genes using a case-control approach in puerperal psychosis and bipolar affective disorder probands. METHODS: We genotyped 320 female participants (104 puerperal psychosis probands, 102 bipolar disorder participants and 114 controls) at the serotonin transporter SERT (5-HTT) 5-HTTVNTR and 5-HTTLPR locus; serotonin receptor 2A (5-HT2A)-T102C and His452Tyr loci, the serotonin receptor 2C (5-HT2C)-Cys23Ser locus, and seven unrelated Alu polymorphic markers. RESULTS: We observed an association of the puerperal psychosis phenotype with the allele 10 of 5-HTTVNTR of SERT (P=0.004) and a modest association with the genotypic frequencies of the 5-HTTLPR (P=0.036). A nominal P value of 0.006 was observed with the S-10 haplotype in the PP group as compared with bipolar affective disorder probands. Significant association was observed with bipolar affective disorder phenotype with Tyr allele of the 5-HT2A His452Tyr gene polymorphism (P=0.00043) even after a conservative multiple test correction. No association was observed, however, with the 5-HT2A T102C locus, and the distribution of the other seven Alu markers did not differ between the groups. CONCLUSION: The association between polymorphisms in serotonergic genes (SERT and 5-HT2A, 5-HT2C) suggests that these genetic factors can modulate vulnerability to puerperal psychosis in female bipolar participants.
