VARIOUS types of interchromosomal structural rearrangements now have been described in man. Transfer of genetic material from one chromosome to a nonhomologous chromosome generally involves breakage and subsequent reunion, with reciprocal exchange of the broken parts. This report describes an unusual translocation between chromosome 2 and a D-group chromosome (46, XX, t [29 −; Dq +]) in a child with profound mental retardation, failure to thrive, and other congenital anomalies. The presence of an abnormal phenotype suggests that translocation karyotype is an "unbalanced" one.
Report of a Case
This 27-month-old Negro girl was born at term to a 24-year-old unwed mother. Blood group incompatibilities indicated that the presumptive 32-year-old father of the propositus was not the biological father. The mother had vaginal bleeding for several days at six months' gestation, but the remainder of the pregnancy was uneventful. There was no history of drug ingestion, infection, or x-ray exposure during the
Reisman LE, Kasahara S. An Unusual Chromosome Abnormality: 2/D Translocation. Am J Dis Child. 1968;115(5):625–628. doi:10.1001/archpedi.1968.02100010627018
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