Search

Recent advances in the field of genomics have seen the successful implementation of whole exome sequencing as a rapid and efficient diagnostic strategy in several genodermatoses. The aim of this study was to explore the potential of molecular studies in dystrophic epidermolysis bullosa (DEB) in India. Whole exome sequencing was performed using genomic DNA from each case of epidermolysis bullosa, followed by massively parallel sequencing. Resulting reads were mapped to the human reference genome hg19. Sanger sequencing subsequently confirmed the potentially pathogenic mutations. Whole exome sequencing of 18 patients with DEB from 17 unrelated Indian families revealed 20 distinct sequence variants in the COL7A1 gene including 2 widely prevalent mutations. Dominant inheritance was seen in 7 patients, while 11 patients showed a highly variable recessive DEB. This preliminary study using exome sequencing is clearly encouraging and will serve as the basis for future large-scale molecular studies to actively identify and understand DEB in the Indian population. [ABSTRACT FROM AUTHOR]

5p deletion syndrome or Cri du Chat syndrome is a autosomal deletion syndrome, caused by the de novo deletion of chromosome 5p in the majority of the cases. Clinical features include developmental delay, microcephaly, subtle facial dysmorphism and high-pitched cry. With the advent of newer techniques such as multiplex ligation-dependent probe amplification, rapid diagnosis is possible and chromosomal microarray helps in accurate delineation of the breakpoints. In this study, we characterized probands from two Indian families who had duplication of another chromosome in addition to deletion of 5p region. In the first family, two females of 3 and 5 yr of age had deletion of 5p15.33p15.2 (14.7 Mb) and duplication of 8q24.21q24.3 (15.4 Mb). Proband in the second family was a 2-year-old female and had deletion of 5p15.33p14.3 (22.55 Mb) along with duplication of 12p13.33p13.31 (7.7 Mb). In both the families, father was balanced translocation carrier of the chromosomes involved. Patients in family 1 had overwhelming features of 5p deletion while patient in family 2, besides having features of 5p deletion, showed many features of 12p duplications. Prenatal diagnosis was possible in both the families. To the best of our knowledge, this is the first detailed molecular cytogenetic analysis and prenatal diagnosis report of 5p deletion syndrome from India.