The spectrum of cardiac anomalies in Noonan syndrome as a result of mutations in the PTPN11 gene.
OBJECTIVE
Noonan syndrome is a clinically homogeneous but genetically heterogeneous condition. Type 1 Noonan syndrome is defined by the presence of a mutation in the PTPN11 gene, which is found in approximately 40% of the cases. Phenotype descriptions and cardiac defects from cohorts with Noonan syndrome were delineated in the "pregenomic era." We report the heart defects and links to gene dysfunction in cardiac development in a large cohort of patients with type 1 Noonan syndrome.


METHODS
This was a retrospective, multicenter study based on clinical history, pictures, and medical and cardiologic workup over time. Data were collected by referral geneticists. Mutation screening was performed by direct sequencing of exons 2, 3, 4, 7, 8, 12, and 13 and their intron-exon boundaries, which harbor 98% of identified mutations the PTPN11 gene.


RESULTS
A PTPN11 gene mutation was identified in 104 (38.25%) of 274 patients with Noonan syndrome. Heart defect was present in 85%. The most prevalent congenital heart defects were pulmonary valve stenosis (60%), atrial septal defect, ostium secundum type (25%), and stenosis of the peripheral pulmonary arteries (in at least 15%). Pulmonary valve stenosis and atrial septal defect, ostium secundum type, were significantly associated with the identification of a mutation in the PTPN11 gene. Ventricular septal defect and most left-sided heart defects showed a trend toward overrepresentation in the group without a mutation.


CONCLUSIONS
We compared our data with previous series and integrated the comprehension of molecular PTPN11 gene dysfunction in heart development.
Sznajer
Yves
Y
Department of Medical Genetics, AP-HP Robert Debré University Hospital, Paris, France.
Keren
Boris
B
Baumann
Clarisse
C
Pereira
Sabrina
S
Alberti
Corinne
C
Elion
Jacques
J
Cavé
Hélène
H
Verloes
Alain
A
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006330:Heart Defects, Congenital / Q000145:classification / Q000453:epidemiology / Q000235:genetics*; D006344:Heart Septal Defects, Atrial / Q000235:genetics; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D008297:Male; D009154:Mutation / Q000235:genetics*; D009634:Noonan Syndrome / Q000145:classification / Q000453:epidemiology / Q000235:genetics*; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases / Q000235:genetics*; D011666:Pulmonary Valve Stenosis / Q000235:genetics; D012189:Retrospective Studies
D047908:Intracellular Signaling Peptides and Proteins; C516724:PTPN11 protein, human; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases