Full trisomy 22 in a newborn infant.

Karyotype 47,XY,+22 was found in a newborn infant with primitive and low-set ears, bilateral preauricular pit, broad nasal bridge, antimongoloid palpebral fissures, macroglossia, enlarged sublingual glands, cleft palate, micrognathia, clinodactyly of the fifth fingers, hypoplastic finger nails, hypoplastic genitalia, short lower limbs, bilateral sandal gap and deep plantar furrows. The child developed signs of congenital heart disease and died at the age of 10 weeks. Non-disjunction studies showed maternal origin (meiosis I) of the extrachromosome.

Cytogenetic studies in myelomatosis.

Cytogenetic studies have been carried out on bone marrow aspirates from 25 patients with myelomatosis. Abnormal stem lines were present in 7 of the patients; the remainder had a diploid chromosome complement. In most patients - also in those without an abnormal clone - some metaphases had a blurred appearance similar to that seen in bone marrow aspirates from patients with acute leukaemia. In many of the chromosome preparations obtained before cytostatic therapy some metaphases with structural aberrations on the chromosomes were seen. Evidence is presented that in the patients with abnormal stem lines in the bone marrow, the chromosome abnormalities are confined to the myeloma cells and are not found in the erythrocytic or granulocytic precursors, which thus do not seem to be involved by the neoplastic process. Based on the present resuts and on a review of the relevant literature some general cytogenetic features are emphasized which may contribute to a better understainding of the disorder. Especially, it is demonstrated that in myelomatosis the cytogenetic changes are much more uniform than in other malignant disorders with the exception of chronic myeloid leukaemia.