The Autopsy Findings of Ten Cases with Meckel Gruber Syndrome: A Prospective Study
H Akgun, MT Ozgun, A Tasdemir, F Ozturk, M Basbug. Erciyes University Medical Faculty, Kayseri, Turkey
Background: Meckel Gruber syndrome (MGS) characterized by the cystic renal dysplasia, occipital encephalocel, and postaxial polydactyly. Due to the recurrence risk of 25%, it deserves an exact diagnosis. Although a confident diagnosis is possible only when the syndrome recurs in subsequent pregnancies, the Meckel Gruber syndrome can usually be suggested on the basis of characteristic pathologic findings and a normal karyotype. This emphasizes the importance of prenatal sonography and a careful postmortem examination to establish the correct diagnosis.
Design: In a 6-year long prospective study, we examined fetal autopsy findings in ten fetuses with MGS out of 118 second-trimester termination of pregnancy cases due to fetal malformation diagnosed by second trimester-ultrasound examination at a tertiary referral center.
Results: Ten fetuses with MGS were analyzed. Nine cases had classical clinic triad. One case had only cystic renal dysplasia and polydactyly. Occipital encephalocel was present in nine cases and in one of them there were combine anomalies with encephalocel and Dandy Walker syndrome. The renal malformations characterized by a bilateral, symmetrical enlargement of the kidneys with abdominal distension and lung compression. The renal parenchyma was diffusely cystic throughout the cortex and the medulla. It contained small and medium-sized, thin-walled cysts that varied a great deal in diameter. Five cases showed ductal plate malformation of the liver with a variable degree of dilatation of the primitive biliary structures. Additional anomalies included cleft plate (n=1), micrognatti (n=1), hypoplastic left ventricule (n=1) , placental hemangioma (n=1), and clubfoot (n=1).
Conclusions: Autopsy provides valuable differential diagnostic information and can be used to validate obstetric management and to evaluate the recurrence risk in future pregnancies in MGS. The differential diagnosis of MGS should include trisomy 13, Zellweger syndrome, Smith Lemli-Opitz Syndrome, Agostino syndrome and Jeune syndrome. Morphological, karyotypic and genetic analyses are necessary for differentiation. If histological examination of the kidneys and liver are performed, the diagnosis of MGS can be made. Cases with MGS, parents should be counseled for their further pregnancy, that they have a risk of 25% recurrence, due to its autosomal recessive transmission nature, and an early targeted sonograph should be advised in future pregnancies.
Wednesday, March 11, 2009 1:00 PM
Poster Session VI # 5, Wednesday Afternoon