Methods-A large family is described in which mental retardation segregates as an X linked trait. Six aVected males in three generations were studied by linkage and clinical examination. Results-Characteristic clinical features include short stature, prominent lower lip, small testes, muscle wasting of the lower legs, kyphosis, joint hyperextensibility, abnormal gait, tremor, and decreased fine motor coordination. AVected subjects also had impaired speech and decreased attention span. A carrier female was mildly aVected. A similar disorder was not found on review of our XLMR Database of 124 syndromes. Linkage analysis of 37 markers resulted in a lod score of 2.80 at DXS1212 and 2.76 at DXS425. The limiting markers were DXS424 and DXS1047. Ten of 124 XLMR syndromes and eight of 58 MRX families overlap this region. Conclusions-In summary, this family appears to have a new XLMR syndrome localising to Xq24-q25.

The computer database on X-linked mental retardation (XLMR) disorders developed by Arena and Lubs in 1991 has now been updated to include all currently known XLMR disorders and nonspecific (MRX) families. Currently, it includes 123 syndromes, 59 nonspecific XLMR families, and 60 families from the Miami/Greenwood study. The older clinical reports have been reviewed and revised. The search mechanism has also been revised and now includes 740 individual "keywords." Each of these keywords recognizes several of clinical descriptive terms, as used in published literature reports. Searches can be made according to any clinical finding or combination of findings. For each disorder, the database presents a graphic display that contains a revised and more complete set of clinical findings, references, keywords, map localization, molecular information, access to pictures, and OMIM number.