Renal involvement in children with HNF1ß mutation: early sonographic appearances and long-term follow-up.

ABSTRACT

OBJECTIVES: The aim was to report ultrasound (US) patterns of hepatocyte nuclear factor (HNF1ß) mutation throughout childhood and determine whether ultrasound could be predictive of renal failure. METHODS: The sonographic examinations in 34 children with HNF1ß mutation were reviewed. Their sonographic characteristics were compared with renal function. RESULTS: At first postnatal examination renal length was normal in 44 % of the patients, decreased in 24 %, increased in 12 % and asymmetrical in 20 %. Renal cortex was hyperechoic in 97 %. Corticomedullary differentiation was abnormal in 59 %. Cysts were present in 77 % of patients. Cysts were mostly subcapsular (64 %). Twenty-eight patients had follow-up examinations. A modification of the sonographic appearance was observed in 91 % of patients. Eight patients (23 %) had renal failure; no specific US pattern could be demonstrated. CONCLUSIONS: At birth, HNF1ß mutation was typically associated on US with the combination of hyperechoic, normal-sized kidneys with abnormal corticomedullary differentiation (CMD) and multiple cortical cysts. In older children, the appearances can be variable kidneys may have decreased (32 %) or normal size (33 %); they are usually hyperechoic (50 %) with abnormal CMD (78 %) and (sub)cortical cysts (71 %). No pattern appears to be associated with renal failure. KEY POINTS • HNF1ß mutations determine significant anomalies of sonographic appearances of kidneys in children. • Kidneys appear mainly hyperechoic, with or without CMD and with subcapsular cysts. • The US pattern may evolve throughout childhood in the same patient. • No correlation was found between any sonographic pattern and renal failure.