Research Explained: Dual molecular diagnosis of tricho-rhino-phalangeal syndrome type I and Okur-Chung neurodevelopmental syndrome in one Chinese patient: a case report

Authors: Shanshan Xu, Jinzhun Wu, Lingli Lu, and Jia Song.

Publication Date: August 3, 2020

Research Explained By: Brad Davidson, CSNK2A1 Foundation Science Communication Intern

Link to article: https://bmcmedgenet.biomedcentral.com/articles/10.1186/s12881-020-01096-w

Research Explained Summary:

This case report describes the co-occurrence of two genetic diseases in one patient, including both OCNDS and tricho-rhino-phalangeal syndrome (TRPS). It also follows the clinical analysis of both parents of the patient to determine the origins of these two rare diseases. The patient first presented to a pediatric endocrinology clinic at almost 7 years old with short stature and developmental delay. Upon presentation, he displayed sparse scalp hair, short stature, and severe intellectual disability, although many blood tests for various physiological variables were normal otherwise. Prior to this, he suffered from developmental delays including walking for the first time and speaking at 4 years of age. He started school at 6 years old but couldn’t communicate with the other children.

Genetic testing revealed two mutations that could be disease causing, one in the CSNK2A1 gene (the K198R mutation, the most common in OCNDS), and the TRPS1 gene. The patient’s father has a mild intellectual disability and short stature. Upon genetic testing, the father was found to have the same CSNK2A1 gene mutation as the patient, indicating that the patient inherited it from his father. His mother has sparse scalp hair, short stature, and facial features characteristic of TRPS. Via genetic testing, the mother was found to have the same mutation as the patient in the TRPS1 gene, indicating that the patient inherited TRPS from his mother. Both TRPS and OCNDS present variably in individual patients, although both diseases are characterized by short stature – the patient described herein was extremely short, likely due to a combination of both diseases. This report is the first to describe OCNDS coinciding with another rare disease.