Murphree, Marine I.

AbstractWhole exome sequencing (WES) has become a fundamental component of genetic evaluation and diagnosing rare genetic diseases. This test is now offered to patients from a wide variety of cultural backgrounds and in various clinical and research settings. This commentary is a reflection of one group of clinical genetic counselors’ experiences in facilitating WES for patients who come from outside the United States for genetic evaluation and pursue WES. This patient population in our clinic primarily consists of individuals from the Middle East and presents recurrent logistical and counseling challenges. We aim to describe our international patient population, illuminate the challenges we have faced and illustrate how we have addressed these challenges.

SOX2 is a transcription factor that is essential for maintenance of pluripotency and has several conserved roles in early embryonic development. Heterozygous loss‐of‐function variants in SOX2 are identified in approximately 40% of all cases of bilateral anophthalmia/micropthalmia (A/M). Increasingly SOX2 mutation‐positive patients without major eye findings, but with a range of other developmental disorders including autism, mild to moderate intellectual disability with or without structural brain changes, esophageal atresia, urogenital anomalies, and endocrinopathy are being reported, suggesting that the clinical phenotype associated with SOX2 loss is much broader than previously appreciated. In this report we describe six new cases, four of which carry novel pathogenic SOX2 variants. Four cases presented with bilateral anophthalmia in addition to extraocular involvement. Another individual presented with only unilateral anophthalmia. One individual did not have any eye findings but presented with a suprasellar teratoma in infancy and was found to have the recurrent c.70del20 mutation in SOX2 (c.70_89del, p.Asn24Argfs*65). This is this first time this tumor type has been reported in the context of a de novo SOX2 mutation. Notably, individuals with hypothalamic hamartomas and slow‐growing hypothalamo‐pituitary tumors have been reported previously, but it is still unclear how SOX2 loss contributes to their formation.