#322 : A Rare Case Report of Successfull Live Twin Birth in a Couple Who are Carriers of Mucopolysaccharidoses VII-Sly Syndrome

Abstract

Introduction: Mucopolysaccharidoses VII or sly syndrome is an autosomal recessive condition discovered in 1972 by William Sly, occurs due to mutation in the beta glucoronidase encoding gene, it is an ultra-rare neurometabolic disorder caused by inherited deficiency of the lysosomal enzyme [Formula: see text]eta-glucuronidase. Precise data regarding its epidemiology is scarce, but birth prevalence is estimated to vary from 0.02 to 0.24/100,000 live births with 54 types of recorded mutations. The clinical course and disease progression are widely heterogeneous. So far 9 pregnancies have been recorded in patients with sly syndrome of which the majority showed some deformity. Here we present a case of a couple with two different variants of GUSB gene who delivered live twin birth with normal development. Background: A couple aged 29 & 31 who were anxious to conceive came to the clinic with a previous history of two abortions for pre conceptual counselling. Both pregnancies had features suggestive of non-anemic type nonimmune hydrops with increased nuchal fold thickness in USG. Both her pregnancies were terminated mid trimester with the autopsy results conclusive of the findings. Method & Results: Whole exome sequencing showed that both were carriers of GUSB gene of two different variants encoding for Sly syndrome. Based on the WES and karyotyping reports genetic counselling was given, and PGT-M was suggested. The patient underwent antagonist protocol and 12MII were retrieved. ICSI was done and the embryos were cultured to day 5 and subjected to PGT-A, PGT-M. The resultant 2 carrier blastocysts were transferred. Post transfer Beta Hcg was positive. The patient had an uneventful obstetric course and delivered normal twin girl babies on 27/01/23. The twins showed no physical abnormality and their genetic profiling showed they were carriers of GUSB gene. Conclusion: This case demonstrates that with appropriate pre-conceptual evaluation, genetic counselling, constant maternal and fetal surveillance, carriers of sly syndrome can be given multidisciplinary care leading to successful outcome.