Hyperechogenic kidneys and polyhydramnios associated with HNF1B gene mutation

• Published in: Pediatric nephrology (Berlin, West) Vol. 31; no. 10; pp. 1705 - 1708
• Main Authors: Gondra, Leire, Décramer, Stéphane, Chalouhi, Gihad E., Muller, Françoise, Salomon, Rémi, Heidet, Laurence
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-10-2016; Springer; Springer Nature B.V
• Subjects: Adult; Amniotic fluid; Autopsies; beta 2-Microglobulin - blood; Brief Report; Congenital diseases; Development and progression; DNA binding proteins; Esophagus; Families & family life; Female; Fetus; Fetuses; Gene Deletion; Gene mutation; Genetic aspects; Gestational diabetes; Hepatocyte Nuclear Factor 1-beta - genetics; Histology; Humans; Infant, Newborn; Infant, Premature; Kidney - diagnostic imaging; Kidney diseases; Medicine; Medicine & Public Health; Mutation; Nephrology; Pediatrics; Phenotype; Physiological aspects; Polyhydramnios - diagnostic imaging; Polyhydramnios - genetics; Polyuria; Pregnancy; Pregnancy Trimester, Second; Pregnancy Trimester, Third; Premature birth; Ultrasonic imaging; Ultrasonography, Prenatal; Urodynamics; Urology; France; United States > US; Paris France; HNF1B; Kidneys; Polyhydramnios; Amniotic fluid; Hyperechogenic
• ISSN: 0931-041X; 1432-198X
• DOI: 10.1007/s00467-016-3421-6

Background
HNF1B
mutation is the leading cause of isolated hyperechogenic fetal kidneys with normal or moderately large size. Although most cases have normal amniotic fluid volume, some cases present with early oligohydramnios and renal failure associated with high perinatal mortality.
Case Diagnosis/Treatment
Here we report on seven fetuses from six unrelated families, carrying an
HNF1B
mutation, and presenting with polyhydramnios during the second or third trimester of pregnancy. Polyhydramnios was transitory in two cases. None of the mothers was presenting gestational diabetes. Bilateral hyperechogenic kidneys with size between −2.5 and +2 SD was the most common renal phenotype at prenatal US. Two patients were born prematurely at 28 and 32 weeks of gestation, respectively. Both presented high urine output the first days of life with urinary salt and potassium loss requiring hydro-electrolytic compensation. All mutations were large deletions removing the whole
HNF1B
gene.
Conclusions
In the absence of maternal diabetes,
HNF1B
mutation can be associated with polyhydramnios, probably due to fetal polyuria. Thus,
HNF1B
mutation represents a differential diagnosis of polyhydramnios associated with hyperechogenic (and sometimes enlarged) kidneys.