A homozygous loss-of-function mutation in PTPN14 causes a syndrome of bilateral choanal atresia and early infantile-onset lymphedema: PTPN14 mutation in lymphedema-choanal atresia

- The new homozygous truncating mutation in PTPN14
- This report confirms the causality of PTPN14 mutations as pathogenic variant.
- This is the 2nd case with “choanal atresia and lymphedema syndrome” worldwide.
- This report expands the clinical phenotype of this rare genetic syndrome.
- In contrast to the 1st reported family, the patient displays lymphedema at early age.

A homozygous truncating mutation in nonreceptor tyrosine phosphatase 14 (PTPN14) has recently been associated with an extremely rare autosomal recessive syndrome of congenital posterior choanal atresia and childhood-onset lymphedema. PTPN14 has been shown to interact directly with the vascular endothelial growth factor receptor 3 (VEGFR3), a receptor tyrosine kinase essential for lymphangiogenesis. Here we present an Iranian family with a single child affected by high-arched palate, congenital hypothyroidism, dysmorphic face, bilateral choanal atresia and infantile-onset lymphedema. Screening of the PTPN14 revealed a novel homozygous frameshift mutation in exon 4 predicted to result in premature truncation of the polypeptide product, which segregated with the disease phenotype. To our knowledge, this is the second family with “choanal atresia and lymphedema syndrome” to be reported worldwide. In contrast to the first reported family that showed lymphedema in late childhood, the patient described here displays lymphedema in her lower limbs at early infancy associated with growth delay, mild facial swelling, congenital hypothyroidism and some minor developmental abnormalities. This report confirms the causality of PTPN14 loss-of-function mutations and further expands the clinical phenotype of this rare genetic syndrome.