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Germinal mosaicism in Noonan syndrome: A family with two affected siblings of normal parents
Author(s) -
Elalaoui Siham Chafai,
Kraoua Lilia,
Liger Céline,
Ratbi Ilham,
Cavé Hélène,
Sefiani Abdelaziz
Publication year - 2010
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.33685
Subject(s) - ptpn11 , noonan syndrome , short stature , mutation , genetics , protein tyrosine phosphatase , biology , gene , endocrinology , receptor , kras
Noonan syndrome (NS; OMIM 163950) is an autosomal dominant disorder with variable clinical expression and genetic heterogeneity. Clinical manifestations include characteristic facial features, short stature, and cardiac anomalies. Mutations in protein‐tyrosine phosphatase, non‐receptor‐type 11 ( PTPN11 ), encoding SHP‐2, account for about half of NS patients. We report on a Moroccan family with two children with NS and apparently unaffected parents. The molecular studies showed the heterozygous mutation c.922A>G of PTPN11 gene in the two affected sibs. Neither the parents, nor the oldest brother carries this mutation in hematologic cells. The mutation was also absent in buccal epithelial cells and fingernails of both parents. We believe this is the first report of germ cell mosaicism in NS and suggest an empirical risk for recurrence of that is less than 1%. © 2010 Wiley‐Liss, Inc.