Familial occurrence of congenital malformations and ring chromosome (46,XX,Cr).

A human ring C chromosome associated with multiple congenital abnormalities.

“…The nonspecific findings in our patient are not helpful in this regard. Comparison of both the phenotypic and the chromosomal findings in our patient with those from the literature indicate that microcephaly and mental and physical retardation is a common pattern in these patients (Turner et al, 1962;Atkins et al, 1966;Bueno, Del Amo, and Hermida, 1969;Gacs, Schuler, and Sellyei, 1970). The lack of a common phenotype is not surprising and could be due to involvement of different C group chromosomes or alteration of different parts of the same chromosome in the formation of the ring structure.…”

Physical retardation is associated with ring chromosome mosaicism: 46, XX,r(10)/45, XX,10 minus.

“…The clinical anomalies observed in this patient were strikingly mild and included short stature, small head circumference, widely spaced nipples, and pectus excavatum. One or more of the physical anomalies have been cited by others in association with ring C chromosomes (Gacs et al, 1970;Moore et al, 1973;Zackai and Breg, 1973). However, in all instances there were additional abnormalities that were not present in our case, or the chromosome involved was not chromosome 10.…”

“…Most reports of ring C chromosomes have not identified the specific chromosome involved, and the clinical features associated with them have been variable (Atkins et al, 1966;Gacs et al, 1970;Therkelsen et al, 1971). Moore et al (1973) and Fried et al (1975) described rings derived from chromosome 6 using quinacrine and ASG banding, respectively.…”

Developmental Abnormalities Associated with a Ring Chromosome 6

“…While ring chromosomes are rare, they have been observed in each of the seven chromosomal groups, including at least 10 cases in the C group (Turner et al, 1962;Smith-White et al, 1963;Atkins et al, 1966/67;Butler, France, and Jacoby, 1967;Bueno, del Amo, and Hermida, 1969;Wurster et al, 1969;Gacs, Schuler, and Sellyei, 1970;Kistenmacher and Punnett, 1970;Therkelsen, M0ller, and Henningsen, 1971; de Chieri et al, 1972). None of the Cgroup chromosomes involved in the ring formation was identified.…”