De Novo Missense Mutation in FREM1 Identified in a Chinese Patient with Comorbid Congenital Microtia and Pulmonary Hypoplasia

Cases of microtia combined with pulmonary hypoplasia are occasionally in clinics, and its genetic etiology has so far proved inconclusive. Here, aiming to contribute to a better understanding of microtia-related comorbid respiratory anomalies, the authors provide a clinical and genetic description of a rare trio family of which the son suffers combined deformities of right microtia, left pulmonary hypoplasia, and dextrocardia using whole-genome sequence (WGS). A novel potential pathologic compound heterozygosity in the FREM1 gene was identified and validated by the trio and bioinformatics analysis. This case expands the FREM1 mutation genotype and phenotype spectrum, sheds light on the congenital deformities of microtia and pulmonary hypoplasia, and emphasizes the importance of the FREM1 gene in pulmonary and craniofacial development.