Dialysis modality for patients with Turner syndrome and renal failure

Renal morphology and function from childhood to adulthood in Turner syndrome

BACKGROUND

Turner syndrome (TS) is a chromosomal disorder with various complications, including congenital anomaly of the kidney and urinary tract (CAKUT). However, its renal function remains poorly known. Therefore, this study aimed to evaluate renal function in TS of various ages from childhood to adulthood.

METHODS

We retrospectively analyzed 63 patients with TS who visited our hospital between 1989 and 2020, examined their renal morphology, and analyzed renal function by calculating the estimated glomerular filtration rate (eGFR) using formulas applicable for Japanese populations.

RESULTS

Renal morphological abnormality was observed in 22 cases (35.0%) (horseshoe kidney, 7 [11.1%]; hydronephrosis, 11 [17.5%]; duplex collecting system, 3 [4.8%]; and single unilateral kidney, 1 [1.6%]). We evaluated the eGFR of 47 subjects aged 2.8-39.3 years and classified them into Group 1 (with CAKUT, n = 15) and Group 2 (without CAKUT, n = 32). The eGFR at the first visit and the final follow-up was not statistically different between these groups. In Group 1 with CAKUT, the eGFR was not significantly different between that at the first visit and that at the final follow-up (p = 0.21). During the observation period (median, 7.9 years), the eGFR of all individuals in both groups gradually decreased with age, but did not fall < 60 mL/min/1.73 m², which defines chronic kidney disease (CKD).

CONCLUSIONS

The renal function of TS remained normal in all cases during our investigation period, and no one developed CKD by the age of 40 years.

Retrospective study of the renal function using estimated glomerular filtration rate and congenital anomalies of the kidney-urinary tract in pediatric Turner syndrome

Although Turner syndrome (TS) is frequently associated with congenital anomalies of the kidney-urinary tract (CAKUT), which is a major cause of pediatric chronic kidney disease, renal function in TS is usually considered normal. The present study aimed to analyze the frequency of renal dysfunction and CAKUT in pediatric patients with TS. Our study included 122 patients with TS between the ages of 2 and 18 years from 30 hospitals across Japan. Clinical data related to renal function and CAKUT were retrospectively collected. The estimated glomerular filtration rate (eGFR) was calculated using the serum creatinine-based formula recommended by the Japanese Society for Pediatric Nephrology. An eGFR <90 mL/min/1.73 m² for two consecutive years was defined as renal dysfunction. Fifteen (13.5%) of 122 patients had CAKUT, and four patients had renal dysfunction (3.2%, 95% confidence interval: 0%-6.7%). Three of the four did not have CAKUT. Of the CAKUT manifestations, horseshoe kidney, renal hypodysplasia, and multicystic dysplastic kidney were seen in nine, two, and one patient, respectively. Eight of the nine patients with horseshoe kidney had a normal renal function; however, the remaining patient with renal hypodysplasia had renal dysfunction. A small percentage of patients with pediatric TS may had an eGFR below 90 mL/min/1.73 m² which was not necessarily associated with CAKUT.