Fluorescence in situ hybridization (FISH) study using probes for Kallmann (KAL), steroid sulfatase, and ocular albinism type 1 all showed nullisomy on Xp22.3 in this patient, and hemizygosity in his older sister, mother, and maternal grandmother.
The results suggest that (1) the gene for chondrodysplasia punctata must lie between the X chromosome pseudoautosomal boundary (PABX) and DXS1145; (2) a gene for mental retardation lies between DXS1145 and the sequence tagged site GS1; and (3) the gene for ocular albinism type 1 lies proximal to the STS G13.
These data suggest that OA1 lies proximal to the deletion in a previously described family with OA1 and STS deletion, but maps within the Xp22.3-Xp22.2 region.