ABSTRACT
A male newborn was investigated for history of antenatal hyperechogenic colon (HEC) detected at 32 weeks of gestation. In the first week of life, urinary ultrasonography showed nephrolithiasis. Urinary amino acid analysis expressed increased excretion of dibasic amino acids, and high urinary cystine levels were detected in both spot and 24-hour urine specimens. He was diagnosed as cystinuria, and genetic analysis of the patient revealed a heterozygous mutation in SLC7A9 gene. Antenatal presentation of cystinuria with HEC is rare and reported to be associated with a more severe disease course.
Subject(s)
Cystinuria , Infant, Newborn , Male , Humans , Female , Pregnancy , Cystinuria/diagnostic imaging , Cystinuria/genetics , Cystinuria/metabolism , Mutation , Colon/diagnostic imagingABSTRACT
Cystinuria is an inherited disease caused by a defect in renal and intestinal tubular transport affecting cystine and dibasic amino acids (lysine, ornithine and arginine). It is transmitted as an autosomal recessive disease. On fetal ultrasound, the colon is usually seen as hypoechoic or isoechoic. Antenatal hyperechoic appearance of the fetal colon was previously considered as a normal variant. However, recent studies have shown that hyperechoic colon is associated with cystinuria. We present a case of cystinuria, who was referred to us due to fetal hyperechogenic colon at 32 weeks of gestation. Additional fetal pericalyceal echogenic focal structures were observed on ultrasonography. The diagnosis of cystinuria was confirmed in the postnatal period.