ESPN 51th Annual Meeting

ESPN 2018


 
Evaluation of phenotypic and genotypic features of distal renal tubular acidosis in children
BAHRIYE ATMIS 1 AYSUN KARABAY BAYAZIT 1 ENGIN MELEK 1 ATIL BI┼×GIN 2 ALI ANARAT 1

1- CUKUROVA UNIVERSITY, FACULTY OF MEDICINE, DEPARTMENT OF PEDIATRIC NEPHROLOGY, TURKEY
2- CUKUROVA UNIVERSITY, FACULTY OF MEDICINE, DIVISION OF MEDICAL GENETICS, TURKEY
 
Introduction:

 Distal renal tubular acidosis is characterized by hypercloremic metabolic acidosis, hypokalemia, hypercalciuria and nephrocalsinosis. We aimed to analyze phenotype and genetic defects in children with distal renal tubular acidosis from Cukurova region, Turkey. 

Material and methods:

 A total of 21 patients from 15 families who have been diagnosed with distal renal tubular acidosis having three causative genes of  SLC4A1, ATP6V1B1, and ATP6V0A4 were included in the study. 

Results:

 A total of 21 patients from 15 families, who have been diagnosed with distal renal tubular acidosis from a single center were included to the study. This study was conducted to evalute of clinical and genetic spectrum of distal renal tubular acidosis in children.  Seventeen children (80.9%) were male.  Fifteen of the patients (71.4%) were diagnosed within the first 3 months. Median age at diagnosis was 3 months (2-36 months). Median follow-up period was 126 months. All of the patients had nephrocalcinosis at the time of diagnosis. The consanguineous marriage frequency was found 80.9%. ATP6V0A4 gene mutations were found in ten of all patients, ATP6V1B1 gene mutations were found in seven of all patients. SLC4A1 gene mutation were found four of all patients. Sensorineural hearing loss was found in seven patients with an ATP6V1B1 mutation. None of the other patients had any hearing loss. The family history of our patients for distal renal tubuler asicodis was found 52.6%.  The presenting symptoms were vomiting, inadequate weight gain, dehydration, fever, rickets and sensorineural hearing loss, respectively. Children with early diagnosis and treatment of dRTA have no  growth retardation.  In our cases in which ATP6V1B1 mutation was detected, deterioration of renal function was seen with advancing age. Four of the seven patients with ATP6V1B1 mutation were over 18 years old and had eGFR <90 ml/min per 1.73m².

Conclusions:

 Children with vomiting, weight gain,  and nephrocalcinosis have to be investigated for dRTA.  Long-term follow-up  of renal function in adulthood  and  genetic screening is necessary for these children.