What is the cause of kidney dysfunction in a newborn with trisomy 21? Answers

Excerpt

Trisomy 21 is associated with congenital anomalies of the kidney and urinary tract (CAKUT) [1, 2]. Furthermore, its estimated glomerular filtration rate (eGFR) is approximately 80% of healthy children [2]. Hepatocyte nuclear factor β (HNF1B) mutations are the most common monogenetic cause of CAKUT and are found in 5–38% of the patients [3]. HNF1B mutations also cause autosomal dominant tubulointerstitial kidney disease (ADTKD). ADTKD is characterized by progressive loss of kidney function, bland urinalysis (absent-to-mild albuminuria/proteinuria), kidney cysts, and initially normal kidney size [4]. In our case, several features not typically found in trisomy 21 together with the mother’s history were the keys to the diagnosis. …