We present four children with a ring chromosome 6. Clinically, these cases are quite variable. A review of ten previously reported cases also suggests difficulty of phenotype-karyotype correlation in patients with a ring 6.

Myelodysplastic syndromes: a scoring system with prognostic significance. Br J Haematol 1985;59:425-33

We present three live-born infants with tetraploidy and compare them with two previously reported live-born infants with the same genetic defect. Common anomalies noted included microcephaly; a prominent, narrow forehead; microphthalmia/anophthalmia; cleft palate; orthopedic anomalies; genital ambiguity; and abnormalities of the central nervous system, including pituitary hypoplasia. Together these constitute a rather characteristic phenotype. An error in cytoplasmic cleavage is theorized to be a mechanism for the chromosome anomaly and is supported by the presence of parental polymorphisms in one of our cases; however, the presence of a small percentage of tetraploid cells in the leukocytes and skin fibroblasts of this patient's mother does not exclude maternal mosaicism as the basis for polyploidy in certain instances.

No abstract

Relatively few cases of deletion 1q have been reported. These cases have been divided into three groups according to assigned breakpoints. They include proximal interstitial, intermediate interstitial, and terminal deletions. We present a male infant with an interstitial deletion of 1q with breakpoints determined by GTG banding as q25 and q32. Comparison with similar case reports suggests common physical features which include microcephaly, growth retardation, developmental delay, clinodactyly, and genital anomalies in affected males. However, no characteristic phenotypic appearance is definable. The infant also presented with prune belly sequence (PBS) with Potter facies. Fetal ascites, as noted in this case on prenatal ultrasound, appears to be an early factor in the pathogenesis of PBS. Therefore, detection of fetal ascites should suggest the presence of the PBS association and the need for more extensive prenatal evaluation.