PARTIAL DELETION OF THE LONG ARM OF CHROMOSOME E-18

Abstract

A male infant with growth failure and multiple somatic abnormalities is described. Karyotype showed deletion of material from the long arm of an autosome identified autoradiographically as a number 18. Abnormalities commonly associated with this chromosome deletion have been mental retardation, growth failure, microcephaly, hypertrophic ear parts, mid-face retraction, increased digital whorls, developmental retardation, ocular anomalies, fusiform fingers, carp mouth, hypoplastic ear canals, and genital abnormalities occurring in males. The subject of this report presented with extreme growth failure and developmental retardation. Mid-face dysplasia was mild and microcephaly was absent. External genitalia were normal though all previously described males had cryptorchidism or penis abnormality. Findings not previously reported are ankylosis in extension of both knees, palatal pigmentation, and an extra thoracic vertebrum. Phenotypic analyses of patients with an 18q- or 18r chromosome suggest that genic loci influencing the development of ear canals and the incidence of digital whorls are located near the ends of the long arms.