A microdeletion in 19q13.2 associated with mental retardation, skeletal malformations, and Diamond-Blackfan anaemia suggests a novel contiguous gene syndrome

Diamond-Blackfan anaemia (DBA) is a constitutional red blood cell. hypoplas ia which may be associated with a variety of developmental abnormalities, a gene for DBA was recently mapped to chromosome 19q13.2 and subsequently cl oned. Analysis of 19q marker alleles in DNA of sporadic DBA cases showed de novo microdeletions in three patients also presenting with mental retardat ion. We have studied one of these patients and characterised the deletion b y fluorescence in situ hybridisation (FISH) to extended DNA fibres. The del etion was shown to be continuous over a 3.2 Mb region and the fibre-FISH an alysis showed both chromosomal breakpoints. in combination, the clinical an d molecular findings suggest a contiguous gene syndrome with a gene locus f or mental retardation and, probably, skeletal malformations included in the deletion.