Clinical phenotype of 20 children with primary distal renal tubular acidosis and their gene analysis

Objective To investigate the clinical phenotype and genetic characteristics of primary distal renal tubular acidosis (dRTA) in children.

Methods Clinical data and genetic test results of 20 children with primary dRTA were retrospectively collected and analyzed.

Results The primary clinical manifestations of the 20 cases were growth retardation, fever, vomiting, fatigue, polydipsia and polyuria, numbness, diarrhea and cough. All the 20 patients had renal medullary calcium deposition, the 2 patients had renal cystic disease, and 7 patients had medullary spongy kidney. All children were treated with citrate mixture. After treatment, the metabolic disorders were corrected in all the children. Whole exon sequencing was performed in 12 cases, and significant gene mutations were detected in 11 cases, and they were homozygous mutations from the parents; the mutation type of the remaining 1 case was not identified. The onset age of SLC4A1 mutation was significantly later than that of ATP6V0A4 and ATP6V1B1 (P=0.019); there were no significant differences in blood pH, blood potassium, blood bicarbonate concentration and blood chlorine laboratory test between two groups (P>0.05).

Conclusion Early diagnosis, early treatment, regular follow-up and timely adjustment of medication are the key to the treatment of primary dRTA. Genetic testing helps to clarify the diagnosis and genetic counseling of primary dRTA.