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A new case of 2q duplication supports either a locus for orofacial clefting between markers D2S1897 and D2S2023 or a locus for cleft palate only on chromosome 2q13‐q21
Author(s) -
Õunap Katrin,
Ilus Tiiu,
Laidre Piret,
Uibo Oivi,
Tammur Pille,
Bartsch Oliver
Publication year - 2005
Publication title -
american journal of medical genetics part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.064
H-Index - 112
eISSN - 1552-4833
pISSN - 1552-4825
DOI - 10.1002/ajmg.a.30890
Subject(s) - gene duplication , locus (genetics) , breakpoint , genetics , biology , soft palate , chromosome , gene , medicine , surgery
Abstract We report on a pure duplication of the proximal chromosome 2q in a 6.5‐year‐old boy with V‐shaped midline cleft palate and bifid uvula, posteriorly located tongue, and micrognathia (Pierre Robin sequence), celiac disease, failure to thrive, and developmental delay. Cytogenetic and FISH analysis indicated a duplication of chromosome 2q13‐q22. In general, pure proximal duplication or triplication of 2q is rare. The clinical features and chromosomal breakpoints of the 10 previously reported patients varied, and no common phenotype or proximal duplication/triplication 2q syndrome could be defined to date. However, based on four previous patients with different orofacial clefts and our case, a locus for orofacial clefting may be located at proximal 2q. The duplication/triplication comprised chromosome 2q13 in all five affected individuals including our patient. Our patient and three previous cases (two with cleft palate only (CPO) and one with cleft lip/palate (CL/P)) showed a cytogenetic breakpoint at 2q13, which could support the presence of a critical dominant gene disrupted by a common breakpoint, however, the fifth case with CPO showed different breakpoints, advocating against the disruption of a critical dominant gene and supporting that the overexpression of a gene(s) on chromosome 2q13‐q21 may cause cleft palate only (CPO) and Pierre Robin sequence. Hence, our findings support either the presence of one locus for orofacial clefting (CL/P, CPO, and Pierre Robin sequence) between markers D2S1897 (chromosome 2q12.2) and D2S2023 (chromosome 2q14.2), or alternatively the presence of a locus for CPO and Pierre Robin sequence on chromosome 2q13‐q21. © 2005 Wiley‐Liss, Inc.