Phenotypic correlations in patients with ring chromosome 22

Abstract

This paper reports two patients with a ring 22 chromosome which has been confirmed by Q‐banding. The literature contains 19 patients with a ring G‐group chromosome which has been shown by chromosome banding to be a ring 22. The most commonly reported features in affected patients have included: retardation with disproportionate verbal delay, reduced head circumference, hypotonia, unsteady gait, large ears with abnormal configuration, and epicanthic folds. The importance of these, as well as other, less often noted findings, is discussed in relation to a possible r(22) syndrome.

Phenotypic variation in two patients with a ring chromosome 22

“…Our first patient manifested many features which have been previously reported in patients with a ring chromosome 22 (Table 1). Her features were particularly similar to those of a patient recently reported by Hunter et al (1977; case 2 in that report); both had a long and bulbous nose, malar hypoplasia, lymphedema, hypotonia, ataxic gait, and profound mental retardation with absence of language. Our second patient was strikingly different, with agility, attractive appearance, and only minimal dysmorphic features, consisting of mild microcephaly, micrognathia, anterior maxillary protrusion, and slight nail hypoplasia.…”

“…Examination of 21 lymphocytes and 11 skin fibroblasts in Patient 2 revealed 46 chromosomes with the presence of a ring chromosome 22 in all cells. Hunter et al (1977); with two additional cases from the literature (Howard-Peebles 1977, Palmer et al 1977).…”

“…A ring chromosome 22 has been reported in at least 23 patients (Weleber et al 1968, Talvik & Mikelsaar 1969, Warren & Rimoin 1970, Richards et al 1971, Chauvel et al 1972, Crandall et al 1972, Magenis et al 1972, Nelson et al 1972, Lindenbaum et al 1973, Stoll et al 1973, Warren et al 1973, Larget-Piet et al 1974, Veal1 et al 1975, Brookfield & Walker 1976, Rethore et al 1976, Stewart & Richards 1976, Howard-Peebles 1977, Hunter et al 1977, Maeda et aI. 1977, Palmer et al 1977.…”

“…1977, Palmer et al 1977. Several patients manifested a distinctive group of features consisting of mental retardation with disproportionate verbal delay, microcephaly and growth failure, epicanthic folds, full eyebrows, dental malocclusion, thick and often fissured lips, large ears with abnormal configuration, cutaneous syndactyly between second and third toes, mild anomalies of spinal curvature, ataxic or unsteady gait, hypotonia, and seizures (Hunter et al 1977). We report here two additional mentally retarded patients with a ring chromosome 22 who manifested differing morphological features despite similar cytogenetic findings.…”

The use of sequential silver and quinacrine staining to determine the parental origin and breakpoints of a ring‐22 human chromosome

“…in the interim (Hunter et al 1977), it is now certain that a "ring-22 syndrome" exists (de Grouchy & Turleau 1977). A recent report by Funderburk et al (1979) demonstrates, however, that there is considerable variability in its expression.…”