Trisomy 22 Mosaicism with Normal Blood Chromosomes

A female infant with growth failure, microcephaly, hypertelorism, epicanthal folds, preauricular pit, congenital heart defect, hypotonia, and delayed development is reported. Trisomy 22 mosaicism (46,XX/47,XX,+22) was found in cultured skin fibroblasts but not in blood lymphocytes. Trisomy restricted to skin fibroblasts is uncommon. Cytogenetic evaluation of a second tissue (preferably skin) is suggested in patients with physical and mental abnormalities who have normal blood chromosome studies.