Partial monosomy 7q34-qter and 21pter-q22.13 due to cryptic unbalanced translocation t(7;21) but not monosomy of the whole chromosome 21: a case report plus review of the literature.

Background: Autosomal monosomies in human are generally suggested to be incompatible with life; however, there is quite a number of cytogenetic reports describing full monosomy of one chromosome 21 in live born children. Here, we report a cytogenetically similar case associated with congenital malformation including mental retardation, motor development delay, craniofacial dysmorphism and skeletal abnormalities.

Results: Initially, a full monosomy of chromosome 21 was suspected as only 45 chromosomes were present.