Abstract
BACKGROUND: WITKOS is a rare neurodevelopmental disorder caused by heterozygous loss-of-function variants in the 15q24.1 - q24.2 region, includeing switch-insensitive 3 transcription regulator family member A (SIN3 A). Its incidence rate is extremely low. According to the current limited global data statistics, only a few cases occur per million population. Most cases concentrate in childhood and adolescence. During this stage, the rapid physiological changes of the body seem to be closely related to the triggering of the disease. Its characteristics include unique facial features, intellectual and motor developmental delay, and short stature. This paper reports a case of WITKOS in a 4-month-old infant caused by large-fragment copy number variation in the 15q24.1 - q24.2 region of the chromosome that encompasses the SIN3 A gene. Gene mutations lead to abnormal functions of key proteins, which subsequently disrupt the normal development and operation of multiple body systems., By summarizing its gene phenotype characteristics, it provides diagnostic and treatment ideas for clinicians to screen for developmentally deviated young children. It is expected to provide more effective treatment options for WITKOS to improve the prognosis of patients. CASE PRESENTATION: This infant was diagnosed with WITKOS at 4 months of age. Subsequently, the manifestations included a wide forehead, a low nasal bridge, low-set ears, growth and intellectual developmental delay, low muscle tone in the limbs, and feeding difficulties. After early rehabilitation training, the language and motor abilities of this infant have been effectively improved, and currently, the infant can walk and run independently and can say short sentences independently. CONCLUSIONS: For children with WITKOS, early diagnosis of the clinical symptoms they exhibit and rehabilitation intervention should be carried out, which can effectively improve the quality of life of the children. This report is the first case of WITKOS caused by a large - fragment deletion, further enriching the case data of WITKOS and highlighting the necessity of strengthening clinical management and monitoring.