Clinical and genetic analysis of a patient with rare nephronophthisis

OBJECTIVE To explore the genetic basis for a child with clinically suspected nephronophthisis (NPHP). METHODS Peripheral blood samples of the patient and her parents were collected subjected to high-throughput sequencing. Sanger sequencing was used to verify the gene variants. RESULTS The patient, a 7-year-old girl with congenital blindness, was admitted to a local hospital due to repeated vomiting for 7-8 days and then transferred to author's hospital due to renal failure. Her urine occult bloods (3+) and urine protein (1+) were abnormal. Her blood urea nitrogen and creatinine showed a significant progressive increase. Renal ultrasound showed a mild enlargement in bilateral renal, increased echogenicity, loss of corticomedullary differentiation, and the presence of cysts in both kidneys. No familial genetic history was found in the family of patient and the child was clinically diagnosed with nephronophthisis. The proband was found to harbor compound heterozygous variants of the CEP290 gene, namely c.2587-2A>T and c.2251C>T, which were inherited from her mother and father, respectively. Based on the ACMG guidelines, both variants were predicted to be pathogenic. CONCLUSION The patient was diagnosed with NPHP type 6 due to variants of the CEP290 gene. Above finding has provided new evidence for the genotype-phenotype correlation of this disease.