Ultraschall Med 2013; 34 - KS_CS6_02
DOI: 10.1055/s-0033-1355012

Discordant Schimmelpenning-Feuerstein-Mims syndrome in monozygotic twins after successful laser coagulation for twin-to-twin transfusion syndrome

H Hubmann 1, C Sommer 1, S Kaddu 2, P Kroisel 3, M Kollmann 4, M Haeusler 4, B Csapo 4, B Urlesberger 1, P Klaritsch 4
  • 1Medical University of Graz, Department of Paediatrics and Adolescent Medicine, Graz, Austria
  • 2Medical University of Graz, Department of Dermatology and Venereology, Graz, Austria
  • 3Medical University of Graz, Institute of Human Genetics, Graz, Austria
  • 4Medical University of Graz, Department of Obstetrics and Gynecology, Graz, Austria

Introduction: Monochorionic twins are by definition monozygotic. Schimmelpenning-Feuerstein-Mims syndrome (SFM) is a rare disorder characterized by sebaceous nevi associated with abnormalities of the central nervous system, eyes and skeleton. We report the third case of discordant occurrence of SFM in monochorionic twins.

Case report: A 35-years-old woman was referred to our institution at 19+3 weeks of gestation due to polyhydramnios in a monochorionic twin pregnancy. Ultrasound examination revealed a twin-to-twin transfusion syndrome (Quintero stage 3) defined by polyhydramnios along with abnormal Doppler flow in the recipient twin and severe oligohydramnios in the donor twin. Fetoscopic laser coagulation of placental anastomoses was successfully performed at 19+4 weeks gestation. The further course of pregnancy was uneventful. At 31+0 weeks preterm premature rupture of the membranes occurred and the recipient twin was born spontaneously at 31+3 weeks while the donor was delivered 15 minutes later by cesarean section due to non-reassuring fetal heart rate. In the donor twin multiple linear sebaceous nevi following Blaschko's lines from forehead to neck and regional alopecia were observed after delivery. Additionally, there were a defective right eyelid with mucosal duplication and epibulbar lipodermoids. Cerebral magnetic resonance imaging displayed regional substance loss of the right cerebral hemisphere and the infant had a low-voltage EEG. However, there were no seizures within the first weeks of life. Renal ultrasound revealed segmental cystic dysplasia in the left kidney, while the co-twin and parents had normal kidneys. Heterozygotic KRAS c.35G>A-mutation was detected confirming the diagnosis of SFM syndrome.

Conclusion: Discordant occurrence of SFM in otherwise genetically identic twins further supports the theory of postzygotic somatic mutation. Besides neurocutaneous manifestations also renal dysplasia may occur in this syndrome.