To explore clinical characteristics and treatment results of a child with distal renal tubular acidosis (dRTA) accompanied by peripheral nerve injury and suspected medullary sponge kidney, and review related literature.

One girl (patient 1) with dRTA accompanied by peripheral nerve injury and suspected medullary sponge kidney who visited West China Second University Hospital, Sichuan University in July 2024 was selected as research subject. Her clinical data were retrospectively analyzed, including medical history, clinical manifestations, laboratory tests and genetic test results, treatment and follow-up results. Literature of children with a confirmed diagnosis of dRTA caused by SLC4A1 gene mutations with peripheral nerve damage and suspected medullary sponge kidney were retrieved with " renal tubular acidosis" " medullary sponge kidney" " peripheral nerve damage" and " SLC4A1" etc. as keywords in CNKI, Wanfang service platform and PubMed database. The procedure followed in this study was in accordance with the requirements of the revised Helsinki Declaration of the World Medical Association. The guardian provides informed consent for the diagnosis and treatment of Patient 1.

①Patient 1 is a 7-year-old female who visited the case collection hospital due to " weakness in both lower limbs for 3 days". The main clinical manifestation of the patient is weakness in both lower limbs, without cough, sore throat, vomiting, diarrhea, lower back pain, limb pain or sensory abnormalities. The results of relevant auxiliary examinations at admission suggest hypokalemia, normal anion gap hyperchlorination metabolic acidosis, elevated muscle enzymes, neurogenic lesions, and suspected medullary sponge kidney. Genetic analysis showed that the patient had a heterozygous mutation of SLC4A1 c. 1765C>T (p.Arg589Cys). Based on her clinical manifestations, auxiliary examinations, and genetic testing results, she was diagnosed as renal tubular acidosis with peripheral nerve damage and suspected medullary sponge kidney. After one month of treatment with oral potassium citrate, B vitamins, and rat nerve growth factor, the patient′s symptoms significantly improved. Reexamination showed that blood gas analysis, electrolyte and muscle enzyme levels have completely returned to normal.②Literature review results: According to the literature search strategy set in this study, no relevant literature reports on children with renal tubular acidosis accompanied by peripheral nerve injury and suspected medullary sponge kidney were found both domestically and internationally.

There are currently no reports of SLC4A1 gene mutations leading to dRTA combined with peripheral nerve damage and medullary sponge kidney. This case proposes the possibility of peripheral nerve damage and medullary sponge kidney being associated with SCL4A1 mutations, which may be a key area for future research. Early completion of WES is of great significance for the early diagnosis of dRTA. Early diagnosis and treatment of children with this disease can improve their prognosis and quality of life.