Exceptional complex chromosomal rearrangements in three generations.

We report an exceptional complex chromosomal rearrangement (CCR) found in three individuals in a family that involves 4 chromosomes with 5 breakpoints. The CCR was ascertained in a phenotypically abnormal newborn with additional chromosomal material on the short arm of chromosome 4. Maternal karyotyping indicated that the mother carried an apparently balanced CCR involving chromosomes 4, 6, 11, and 18. Maternal transmission of the derivative chromosome 4 resulted in partial trisomy for chromosomes 6q and 18q and a partial monosomy of chromosome 4p in the proband. Further family studies found that the maternal grandmother carried the same apparently balanced CCR as the proband's mother, which was confirmed using the whole chromosome painting (WCP) FISH. High resolution whole genome microarray analysis of DNA from the proband's mother found no evidence for copy number imbalance in the vicinity of the CCR translocation breakpoints, or elsewhere in the genome, providing evidence that the mother's and grandmother's CCRs were balanced at a molecular level. This structural rearrangement can be categorized as an exceptional CCR due to its complexity and is a rare example of an exceptional CCR being transmitted in balanced and/or unbalanced form across three generations.

Two novel mutations of SRD5A2 gene in Indonesian siblings with clinical 5-alpha-reductase deficiency.

Steroid 5-alpha-reductase 2 deficiency is an autosomal recessive disorder with clinical spectrum ranges from a male phenotype with hypospadia to a female phenotype with normal wolffian structures. Over 50 different mutations of SRD5A2 gene has been described in affected patients and several mutations were detected in specific populations. DNAs of two 46,XY DSD Indonesian siblings, aged 13 and 18 years old, with clinically suspected of 5-alpha-reductase deficiency and their mother were analysed for molecular defects of SRD5A2 gene. Different from other reports, in our series three mutations were found in each patient. Two novel mutations were detected in these patients and their mother, which are p.Gly34fs and c.699-1G>T. The other mutation detected was c.680G>A or p.Arg227Gln, which commonly described in Far East Asian population. Whether the p.Arg227Gln mutation is considered a polymorphism or a mutation in Indonesian population warrants further study.