关键词: 赖氨酸尿性蛋白耐受不良, 赖氨酸, SLC7A7基因

Abstract: A 6-month-old male child was admitted to hospital due to cough for more than 1 month. The child's growth and development lags behind that of children of the same age. Hepatosplenomegaly existed， and lactate dehydrogenase and alpha-fetoprotein were checked for multiple times and were significantly higher than normal values. Urine orotic acid and uracil slightly increased， and blood ammonia was normal. Chest CT showed interstitial pneumonia. Electron microscope of liver biopsy showed that lipid droplets of different sizes were deposited in some hepatocytes， and many pigment particles were deposited in some hepatocytes. Whole-exome sequencing revealed a compound heterozygous variation in the SLC7A7 gene， and the final diagnosis of lysinuric protein intolerance was made. The disease is a rare autosomal recessive disease. Early diagnosis and timely treatment of the disease can significantly improve the prognosis of children. However， because it often involves multiple systems and lacks specificity in clinical manifestations， it is easy to be missed or misdiagnosed.  Diagnosed cases of small infants are rare. This article summarizes the clinical characteristics， diagnosis and treatment of this patient， and by reviewing relevant literature， provides a reference for the early diagnosis of such disease and the prevention and treatment of  its complications.

Key words: lysineuria protein intolerance, lysine, SLC7A7 gene