Meckel-gruber syndrome on prenatal MRI: A case report

Abstract

Purpose or Case Report: A 24 year-old female presented after having an abnormal prenatal ultrasound at an outside facility. Repeat ultrasound demonstrated multiple fetal malformations including polycystic kidney disease, an occipital encephalocele, polydactyly, club feet, microcephaly, and oligohydramnios. At approximately 26 weeks gestation, a prenatal MRI was also performed. The kidneys were symmetrically enlarged with increased T2- weight signal, consistent with infantile polycystic disease. Additionally, an occipital skull defect was identified with extruding brain contents, compatible with an occipital encephalocele. Additional noted abnormalities included a nonspecific cystic lesionwithin the liver and hypotelorism with abnormal appearing globes, as well as prominent fluid posterior to the globes. The known abnormalities of the extremities were poorly seen on the MRI examination. The incidence of Meckel-Gruber syndrome varies from 1 in 13,250 to 1 in 140,000 live births, and its inheritance is autosomal recessive. The most common features include multicystic kidneys, occipital encephalocele, and polydactyly. The diagnosis is generally considered when polycystic kidneys are present with at least one of the above other abnormalities. Multiple additional abnormalities may be present, including hepatic fibrosis, eye and facial abnormalities, microcephaly, heart defects, club foot, and abnormal genitalia. The final prenatal ultrasound was performed at 38 weeks gestation, again demonstrating these abnormalities. The fetus was carried to term, at which time a C-section was performed. Affected fetuses are commonly stillborn or only survive a few hours after birth. Given the poor prognosis, it is important to recognize the combination of abnormalities as Meckel- Gruber syndrome for clinical planning, family preparation, and future genetic counseling.