Gardner R J, Monk N A, Clarkson J E, Allen G J
Clin Genet. 1986 Dec;30(6):466-70. doi: 10.1111/j.1399-0004.1986.tb01912.x.
The case is reported of a child with the karyotype 46,XY,r(21), who presented with linear growth retardation but who appears, at age 2 years 8 months, to be developing normally mentally. There is a small number of reports of mildly affected cases of r(21), and of some with an apparently completely normal phenotype. We presume a structural and functional cytogenetic heterogeneity underlies the observed phenotypic heterogeneity in the ring 21 spectrum.
报告了一例核型为46,XY,r(21)的患儿，该患儿存在线性生长发育迟缓，但在2岁8个月时智力发育似乎正常。关于r(21)轻度受累病例以及一些表型明显完全正常的病例，已有少量报道。我们推测，21号环状染色体谱系中观察到的表型异质性背后存在结构和功能细胞遗传学异质性。
