[Clinical phenotypes of hepatocyte nuclear factor 1 homeobox b-associated disease]

Objective: Hepatocyte nuclear factor 1 homeobox b (HNF1B) -associated disease is an autosomal dominant inherited disorder with a variable, multi-systemic phenotype. In China, five adult probands and one child proband with HNF1B-associated disease had been reported, whereas few fetuses are described. The aims of this retrospective study were to understand about the clinical manifestations of HNF1B-associated disease and to further improve the recognition of this disorder. Method: Four patients (3 males, 1 female) and three fetuses with HNF1B mutations were included in this study. They were admitted to our hospital from January 2013 to March 2017. HNF1B mutations were detected using targeted next generation sequencing and quantitative real-time PCR or Sanger sequencing. HNF1B heterozygous deletion of exons 1-9 was found in 4 patients and 2 fetuses, and HNF1B heterozygous missense mutation in 1 fetus. These two mutations had been reported. Two patients and 1 fetus had de novo mutations. Results of renal ultrasonography with or without magnetic resonance imaging, biochemical investigations, urine routine examination and other necessary investigations in 7 cases were analyzed. Result: Three patients were Han Chinese ethnicity, and one patient was Mongolian. In patients 1 and 4, abnormal fetal kidneys were discovered by routine ultrasonography, and the age at first feature identified in Patients 2 and 3 were 13 years and 28 years. Patient 3 had normal renal function and the remainder had reduced glomerular filtration rate. In addition, patient 4 presented with nephrotic syndrome and glycosuria, patient 2 with early onset hyperparathyroidism and renal osteodystrophy, and patient 3 with diabetes mellitus. All the 4 patients had renal structural abnormalities including bilateral multiple renal cysts, dysplasia and hyperechogenic kidneys. Only patient 3 had a positive family history of renal diseases, the remainder had a negative family history of renal diseases. In 3 fetuses, prenatal ultrasound anomalies were detected during the second trimester. These 3 fetuses had hyperechogenic kidneys with or without renal cysts. Polyhydramnios was detected in only one of the 3 fetuses. Two of the 3 fetuses had a positive family history of renal diseases. Conclusion: Clinical phenotypes of HNF1B-related disease are heterogeneous, renal malformations clearly appear to be the most common manifestation, multiple renal cysts are characteristic, and patients can progress to impaired kidney function during childhood; HNF1B mutation is a differential diagnosis of fetal hyperechogenic kidneys or multiple renal cysts.