Congenital adrenal hyperplasia, ovarian failure and Ehlers-Danlos syndrome due to a 6p deletion.

Cryptic deletions in balanced de novo translocations represent a frequent cause of abnormal phenotypes, including Mendelian diseases. In this study, we describe a patient with multiple congenital abnormalities, such as late-onset congenital adrenal hyperplasia (CAH), primary ovarian failure and Ehlers-Danlos syndrome (EDS), who carries a de novo t(6;14)(p21;q32) translocation. Genomic array analysis identified a cryptic 1.1-Mb heterozygous deletion, adjacent to the breakpoint on chromosome 6, extending from 6p21.33 to 6p21.32 and affecting 85 genes, including CYP21A2,TNXB and MSH5. Multiplex ligation-dependent probe amplification analysis of the 6p21.3 region was performed in the patient and her family and revealed a 30-kb deletion in the patient's normal chromosome 6, inherited from her mother, resulting in homozygous loss of genes CYP21A1P and C4B. CYP21A2 sequencing showed that its promoter region was not affected by the 30-kb deletion, suggesting that the deletion of other regulatory sequences in the normal chromosome 6 caused a loss of function of the CYP21A2 gene. EDS and primary ovarian failure phenotypes could be explained by the loss of genes TNXB and MSH5, a finding that may contribute to the characterization of disease-causing genes. The detection of this de novo microdeletion drastically reduced the estimated recurrence risk for CAH in the family.

Marfan syndrome with a complex chromosomal rearrangement including deletion of the FBN1 gene.

BACKGROUND: The majority of Marfan syndrome (MFS) cases is caused by mutations in the fibrillin-1 gene (FBN1), mapped to chromosome 15q21.1. Only few reports on deletions including the whole FBN1 gene, detected by molecular cytogenetic techniques, were found in literature. RESULTS: We report here on a female patient with clinical symptoms of the MFS spectrum plus craniostenosis, hypothyroidism and intellectual deficiency who presents a 1.9 Mb deletion, including the FBN1 gene and a complex rearrangement with eight breakpoints involving chromosomes 6, 12 and 15. DISCUSSION: This is the first report of MFS with a complex chromosome rearrangement involving a deletion of FBN1 and contiguous genes. In addition to the typical clinical findings of the Marfan syndrome due to FBN1 gene haploinsufficiency, the patient presents features which may be due to the other gene deletions and possibly to the complex chromosome rearrangement.