Variants in the RNF113A gene are a very rare cause of developmental differences and growth delays in males. A distinctive finding has been thin and easily breakable hair. Other findings can include frequent infections, a smaller head , epilepsy, brain anomalies that can be seen on a brain scan and abnormal kidneys. Boys have had underdevelopment of the genitalia, with failure of the testes to form or descend normally and a smaller penis. Blood tests may show abnormal hormone levels and decreased levels of the blood proteins involved in fighting infections. RNF113A is a relatively small gene that is involved in the process whereby genes are spliced and converted into proteins. It may also be involved in how cells responds to chemicals, including some that are used to fight cancer. RNF113A variants are passed on as an X-linked trait, meaning that affected individuals are typically males and the condition is passed on to them through their mothers.