SPR Unknown # 81-- FINAL
Publication Date: 2013-01-04
Abnormal prenatal imaging
Fetal MRI demonstrates a large cardiac tumor (here rhabdomyoma) of the left ventricular free wall with narrowing of the left ventricle lumen. (Multiple additional cardiac rhabdomyomas were present in this fetus, which are not shown). Single axial T2 weighted image of the brain demonstrate multiple subependymal nodules lining the right ventricle and coronal T1 weighted images of the fetus and brain demonstrate multiple cortical/subcortical regions of increased signal, compatible with cortical/subcortical tubers. Multiple renal cysts are present bilaterally.
Tuberous Sclerosis with mutation of both the TSC2 and PKD1 gene.
– Myxoma - Not typically seen in utero. Usually from the interatrial septum at fossa ovalis with extension into the left atria (85%) more common than the right. Homogeneous and of moderate echogenicity. Isointense on T1 and hyperintense on T2.
• Of all fetal cardiac tumors, approximately 60-80% are rhabdomyoma.
• 2/3 of tuberous sclerosis are from a new mutation.
• 1/3 of cases have an affected parent with a single gene mutation of either TSC1 or TSC2. TS is inherited as an autosomal dominant disorder with variable penetrance.
• Of the cases of tuberous sclerosis, 70% are caused by a mutation in the TSC2 gene (tuberin) which is located on chromosome 19. This gene is in very close proximity to the PKD1 gene which may be affected as well. Therefore, renal cysts are often a prominent feature of TSC2 mutation, however are not usually seen until 7-10 years of age. The number of cysts present in this fetus is unusual. The remaining 30% of TS cases are caused by a mutation in the TSC 1 gene (hamartin) which is located on chromosome 9.
• In general, a mutation in TSC2 is more severe than a mutation in the TSC1 gene.