Answers are grounded in this paper and cite their sources.
An infant with psychomotor retardation, hypertonia, microphthalmia, buphthalmos, cleft palate, nail dysplasia, and hypospadias had the karyotype 46,XY, r(21)/45,XY,‐21. Cytogenetic analysis of prophase and prometaphase chromosomes showed the breakpoints of chromosome 21 were at p12 and q22.2.
No takes yet. Share an insight, caveat, or question.
Richer et al. (1981) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: