Increasing handwriting size (capitalization disorder) is one of the clinical manifestations of cerebellar ataxia causing random motor coordination disorder. Cerebellar ataxia is the most common symptom (hereditary ataxia), and almost 100% of patients with IAs have ataxia. The symptoms caused by random motor coordination disorder should be differentiated by cerebellar ataxia. 1. Isolated renal function is generally difficult to detect in those with good function. One kidney is often found to be absent when B-mode ultrasound or CT examination of both kidneys is performed for some reason. 2.The triangle is asymmetrical during cystoscopy, and the ureteral orifice is absent on one side. 3.Urogram and intravenous urography show no renal shadow or no shadow on one side, and compensatory enlargement of the contralateral kidney. It should be noted to exclude other causes of renal non-show, such as advanced renal tuberculosis and renal hypoplasia. 4, retroperitoneal gas injection angiography, B-type ultrasound and CT examination showed no kidney on one side.