EP18.26: Prenatal diagnosis a rare case of LEOPARD syndrome with double aortic arch caused by uncommon mutation of PTPN11

Multiple lentigines LEOPARD syndrome (LS) (OMIM 151100) is an autosomal dominant multiple congenital anomaly syndrome, with high penetrance and markedly variable expression includes multiple Lentigines, ECG conduction abnormalities, Ocular hypertelorism, Pulmonic stenosis, Abnormal genitalia, Retardation of growth, and sensorineural Deafness. Here we report a case of LS with double aortic arch with uncommon mutation in PTPN11 gene. The finding of an increased nuchal translucency (NT) 7.0mm and cystic hygroma in the first trimester scan prompted evaluation. Amniocentesis was performed with normal CMA. Trios whole exome sequencing (WES) came with a de novo mutation in PTPN11 gene at NM_002834.5: c.1381G>A (p.Ala461Thr). Ultrasound at 21 weeks revealed double aortic arch with small left branch, thick nuchal fold, mild hypertelorism and ectopic right kidney in the pelvis. Both genetic and ultrasound findings were consistent with Leopard syndrome. Very thick NT should prompt WES to rule out RASopathies and related conditions. To our knowledge this is the third case of LEOPARD syndrome with this mutation and the first case of this syndrome is associated with double aortic was reported in literature. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.