MENTAL-RETARDATION IN NANCE-HORAN-SYNDROME - CLINICAL AND NEUROPSYCHOLOGICAL ASSESSMENT IN 4 FAMILIES

Nance-Horan syndrome (NHS) is a rare X-linked condition comprising con genital cataract with microcornea, distinctive dental, and evocative f acial anomalies. Intellectual handicap was mentioned in seven publishe d NHS patients, We performed a clinical study focused on psychomotor d evelopment, intellectual abilities, and behavior in 13 affected males in four NHS families, and present the results of a neuropsychological evaluation in 7 of them, Our study confirms that mental retardation (M R) can be a major component of the NHS. Combining our data with those from the literature leads to a frequency of MR in NHS of around 30%. I n most cases, MR is mild or moderate (80%) and not associated with mot or delay, Conversely, a profound mental handicap associated with autis tic traits may be observed, MR has intra- and inter-familial variabili ty but does not appear to be expressed in carriers. Awareness of MR in NHS may be of importance in the management of the patients, especiall y in terms of education. Cloning and characterization of the gene and analysis of mutations will be an important step towards understanding the molecular basis of mental deficiency in NHS, and in delineation fr om the other XLMR conditions at Xp22. (C) 1997 Wiley-Liss, Inc.