CLINICAL VARIABILITY WITHIN BRACHMANN-DELANGE SYNDROME - A PROPOSED CLASSIFICATION-SYSTEM

Seven patients, including two sibs, with the Brachmann-de Lange syndro me (BDLS) are presented as representative of the different types of BD LS in a proposed classification system. Type I (''classic'') patients have the characteristic facial and skeletal changes of BDLS using the criteria in the diagnostic index of Preus and Rex. Type I is distingui shed from the other subtypes by prenatal growth deficiency (< 2.5 S.D. below mean for gestation) becoming more severe postnatally (< 3.5 S.D . below the mean), moderate to profound psychomotor retardation, and m ajor malformations which result in severe disability or death. Type II (''mild'') BDLS patients have similar facial and minor skeletal abnor malities to those seen in type I; however, these changes may develop w ith time or may be partially expressed. Patients with type II BDLS are distinguished from those with other types by mild to borderline psych omotor retardation, less severe pre- and postnatal growth deficiency, and the absence of (or loss severe) major malformations. Behavioral pr oblems can be a significant clinical problem in type II BDLS. Type III (''phenocopies'') BDLS includes patients who have phenotypic manifest ations of BDLS which are causally related to chromosomal aneuploidies or teratogenic exposures. (C) 1993 Wiley-Liss, Inc.