A PTPN11 Gene Mutation (Y63C) Causing Noonan Syndrome is Not Associated with Short Stature in General Population

Abstract

Ikuko Takahashi1), Maki Utsunomiya2), Kayoko Inoue2), Tsutomu Takahashi1), Jun-Ichi Nozaki2), Yasuhiko Wada3), Goro Takada1) and Akio Koizumi2)

1) Department of Pediatrics, Akita University School of Medicine2) Graduate School of Medicine, Department of Health and Environment Sciences, Kyoto University3) Department of Hygiene, Hyogo College of Medicine

(Received October 3, 2005)(Revision accepted for publication January 18, 2006)

Human growth is a highly complicated process, but it is obviously influenced by a genetic factor. Recent genome-wide linkage analyses suggested some genetic regions underlying stature variations. However, any specific genes underlying stature variations have not been identified. Noonan syndrome (NS) is an autosomal dominant disorder clinically characterized by short stature, minor facial anomalies, and congenital heart defects. Recently, PTPN11 (protein-tyrosine phosphatase, nonreceptor-type 11) has been identified as a major responsible gene for NS, causing about half of the affected individuals. We herein report a large family demonstrating NS caused by one of the common PTPN11 mutations, c.188 A > G (Y63C). In this family, the patients were apparently healthy, but heterozygosity of the c.188 A > G (Y63C) mutation was related to growth impairment. This finding suggested that PTPN11 genetic variants contribute to adult height in the general population. However, c.188 A > G (Y63C) was not identified in 96 short individuals from the general population of 2,281 healthy adults. Thus, it is unlikely that PTPN11 is one of the genes underlying stature variations in the general population.

Noonan syndrome; PTPN11 gene; src homology region 2-domain phosphatase-2 (SHP-2); short stature

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Tokyo Journal of Experimental Medicine

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Mutations of the PTPN11 and RAS genes in rhabdomyosarcoma and pediatric hematological malignancies.

Chen Y, Takita J, Hiwatari M, Igarashi T, Hanada R, Kikuchi A, Hongo T, Taki T, Ogasawara M, Shimada A, Hayashi Y.

Department of Pediatrics, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.

PTPN11 has been identified as a causative gene in Noonan syndrome (NS), responsible for about 50% of cases of NS. Given the association between NS and an increased risk of some malignancies, notably leukemia and probably some solid tumors including neuroblastoma (NB) and rhabdomyosarcoma (RMS), recent studies have reported that gain-of-function somatic mutations in PTPN11 occur in some hematological malignancies, especially de novo juvenile myelomonocytic leukemia (JMML) and in some solid tumors such as NB, although at a low frequency. In a screen for mutations of PTPN11 in 7 cell lines and 30 fresh tumors of RMS and in 25 cell lines and 40 fresh tumors of NB, we identified a missense mutation (A72T) in an embryonal RMS patient.

In the RMS samples, we also detected mutations of NRAS in 1 cell line and 1 patient; both mutations were in embryonal RMSs and had no PTPN11 mutations. No mutations of PTPN11 were detected in NB. In 95 leukemia cell lines and 261 fresh leukemia samples including 22 JMMLs, 9 kinds of missense mutations were detected in 17 leukemia samples, which included 11 (50.0%) mutations in JMML samples and lower frequencies in other hematological malignancies.

Furthermore, we identified 4 (18.2%) NRAS mutations and 1 (4.5%) KRAS mutation in 5 JMML samples, 1 of which had a concomitant PTPN11 mutation. Our data suggest that mutations of PTPN11 as well as RAS play a role in the pathogenesis of not only myeloid hematological malignancies but also a subset of RMS malignancies. (c) 2006 Wiley-Liss, Inc.

PMID: 16518851 [PubMed - as supplied by publisher]