Abstract
Background: To investigate the pathogenesis and clinical characteristics of Oculocutaneous albinism type 2 (OCA2), a genetic condition in the etiology of Prader-Willi syndrome (PWS).Case presentation: A retrospective study of one case presented with poor response to stimuli, difficultfeeding, poor crying, with yellow hair and white skin. We performed genetic testing and investigated disease pathogenesis, clinical manifestations, and diagnosis, and discussed the characteristics of the disease through a literature review. HiSeq high-throughput sequencing result suggested a deletion with 105 genes, including UBE3A, SNRPN, OCA2, and other genes up to 5.18 Mb on the long arm of chromosome (15q11-13 region), a critical region, susceptible to the PWS. A paternally derived deletion Del (15q11. 2q13. 1) [GRCh37 / hg19] (23, 378, 392-28, 563, 050) × 1, and a maternal missense mutation were identified in the OCA2 gene (chr15: 28171296 c .2056G> A (p.A686T). During the period of hospitalization, the child still suffered from poor milk intake, and she was discharged from the hospital at the request of her parents. After discharge, the patient was followed up for two months by telephone. However, the patient died of feeding difficulties and pulmonary infection.Conclusions: OCA2 combined with PWS due to OCA2 gene missense mutation combined with large fragment deletion of 15q11-13 region was first reported in this study, of which the clinical signs can be subtle and symptoms can be more severe, therefore, early genetic testing is crucial for those patients to yield an accurate diagnosis and initiate aggressive interventions to optimize the outcomes.
Oculocutaneous albinism type 2 with a P gene missense mutation in a patient with Angelman syndrome