Rare Combination of PKD and precocious puberty in a HNF1B mutated little girl.

Among the genes involved in ADKPD, HNF1B encodes a transcription factor implicated in kidneys morphogenesis. Here, we present the case of a little girl with multiple renal cysts diagnosed in utero; at 4 years the genetic testing by NGS revealed the rare pathogenic variant c.1462C > T in the HNF1 gene; additionally, overweight and precocious puberty with appearance of pubic hair were suspected. At 7 years, she was obese with right breast bud, adipomastia and accelerated growth. Our experience highlights the diagnostic difficulties associated with an atypical PKD phenotype and underlines the importance of a holistic approach including diagnosis and early therapies.