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Trisomy 12p syndrome Evaluation of a family with a t(12;21)(p12.1;p11) translocation with unbalanced offspring
Author(s) -
Hansteen I. L.,
Schirmer L.,
Hestetun S.
Publication year - 1978
Publication title -
clinical genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 102
eISSN - 1399-0004
pISSN - 0009-9163
DOI - 10.1111/j.1399-0004.1978.tb01190.x
Subject(s) - trisomy , chromosomal translocation , genetics , nose , biology , hypertelorism , microcephaly , karyotype , medicine , anatomy , chromosome , gene
Two brothers (Nos. 1 and 3), with physical and mental retardation and many other clinical characteristics in common, were both trisomic for 12p(ter→12.1) and monosomic for 21p. Their mother (No. 5), the maternal grandmother (No. 7), aunt (No. 8), and a first‐cousin (No. 9) were balanced translocation carriers, 46 rcp (12;21) (p12.1;p11). Another cousin (No. 10) had Down syndrome: he had two normal 21 chromosomes in addition to both translocation chromosomes. A sister (No. 2), who died at the age of 1 year without being karyotyped, had several phenotypical features in common with her brothers. Our two cases of trisomy 12p (ter→12.1) were compared with eight cases of trisomy 12p described earlier, and the following common characteristics were found: severe mental and physical retardation; flat and round, broad face with prominent cheeks; flat and broad nasal bridge with short nose; anteverted nostrils and large philtrum; broad and prominent lower lip; low‐set or slanting ears, poorly formed with folded helix, prominent antihelix and deep concha; short neck; short sternum; “spade”‐shaped fingers, the fifth being short; bilateral genu valgum; bilateral pes planus and talus valgus; increased space between the first and second toes; generalized hypotonia; and certain dermatoglyphic characteristics. An elevated serum lactate dehydrogenase (LDH) was measured in four cases.