Complete trisomy 22

Abstract

Two unrelated girls, aged 6 and 8 yr, are presented with complete trisomy 22 in the absence of detectable mosaicism. In each case, the extra chromosome was unambiguously identified as chromosome 22. The features which were consistent in both girls included: advanced maternal and paternal ages, a history of repeated abortions and stillbirths, normal birthweight with no gross post-natal growth retardation, mental retardation with further severe deterioration at 3-5 yr of age, epilepsy (particularly motor seizures), hypotonia, neurological (especially cerebellar) deficit and abnormal EEG patterns. The physical stigmata comprised: frontal bossing, hypertelorism, bulbous nose, antimongoloid slant of the palpebral fissures, strabismus, long philtrum, large rotated protruding low-set auricles, pectus excavatum,and abnormal dermatoglyphics. The clinical course of the disorder was suggestive of a degenerative phenomenon of the CNS neurons.