Two cases of trisomy 12p due to rcpt(12;21)(p11;p11) inherited through three generations

Abstract

Two cases of trisomy 12p due to a familial translocation t(12;21) (p11;p11) inherited through three generations are presented. The clinical features of both affected individuals are consistent with those previously reported. Study of the NORs by silver staining showed translocation of the NOR from chromosome 21 onto the der(12) and suggested that the activity of this site has been suppressed in some carriers.

A case of de novo trisomy 12p syndrome

“…The oldest patient reported thus far is 18 years old (Suerinck et al 1978). While Bi- jlsma et al (1978) and Parslow et al (1979) noted an "aged appearance" in their patients' photographs (chronological age 16, and 12 years respectively), such "premature aging" is not apparent in our patient.…”

Clinical and molecular cytogenetic observations in three cases of “trisomy 12p syndrome”

“…With respect to facial anomalies, high birth weight, foot deformities, and lack of gross malformations there was no difference between the group with complete and with partial trisomy of 12p. The typical appearance was Kondo et al, 1979;Rethore et al, 1975;Armendares et al, 1975;Alfi and Lange, 1977;Biederman et al, 1977;Suerinck et al, 1978;Parslow et al, 1979;Ray et al, 1985: MR. + + + severe. norm, normal range; xth, xth centile.…”

“…In all of these cases the duplication of 12p involved a reciprocal translocation and was associated with a deficiency of the various recipient chromosomes. However, "pure" trisomy 12p is present when there is deficiency of the short arm of an acrocentric chromosome which is considered inessential [Armendares et al, 1975;Rethore et al, 1975;Alfi and Lange, 1977;Biederman et al, 1977;Tenconi et al, 1977;Hansteen et al, 1978;Suerinck et al, 1978;Parslow et al, 1979;Stengel-Rutkowski et al, 1981;Ray et al, 19851. These cases can be classified together with the observation of a 12p marker chromosome [Kondo et al, 19791 and three cases of tandem duplications [Tayel et al, 1989;Pfeiffer et al, 1992;Leana-Cox et al, 19931.…”

De novo subtelomeric deletion of 15q associated with satellite translocation in a child with developmental delay and severe growth retardation

“…This type of translocation has been reported either as rare familial polymorphisms having no phenotypic effect or de novo translocations with chromosomal loss causing abnormalities. There are several previous reports of satellited autosomes [Parslow et al, 1979;Verma et al, 1979;Watt et al, 1984;Harada et al, 1989;Estabrooks et al, 1992;Arn et al, 1995;Willatt et al, 2001;Ki et al, 2003;Chen et al, 2004a,b]. The most frequent satellited variant autosomes reported to date is chromosome 4 (4qs) [Estabrooks et al, 1992;Arn et al, 1995;Miller et al, 1995;Guttenbach et al, 1999].…”