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BACKGROUND AND PURPOSE: Ganglionic eminence abnormalities on fetal MR imaging are associated with cerebral malformations. Their presumed genetic basis and associated postnatal outcomes remain largely unknown. We aimed to elucidate these through a multicenter study. MATERIALS AND METHODS: Between January 2010 and June 2020, seven hospitals in 2 countries performing fetal MR imaging examinations identified fetal MR imaging studies demonstrating ganglionic eminence enlargement, cavitation, or both. Cases with no genetic diagnosis, no whole exome sequencing, or no outcome of a liveborn child were excluded. Head size was classified as large (fronto-occipital diameter. 95th centile), small (fronto-occipital diameter,5th centile), or normal. RESULT(S): Twenty-two fetuses with ganglionic eminence abnormalities were identified. Of 8 with large heads, 2 were diagnosed with MTOR mutations; 1 with PIK3CA mutation-producing megalencephaly, polymicrogyria, polydactyly, hydrocephalus (MPPH) syndrome; 3 with TSC mutations; 1 with megalencephaly capillary malformation syndrome; and 1 with hemimegalencephaly. Cardiac rhabdomyoma was present prenatally in all cases of TSC; mutation postaxial polydactyly accompanied megalencephaly capillary malformation and MPPH. Of 12 fetuses with small heads, 7 had TUBA1A mutations, 1 had a TUBB3 mutation, 2 had cobblestone lissencephaly postnatally with no genetic diagnosis, 1 had a PDHA1 mutation, and 1 had a fetal akinesia dyskinesia sequence with no pathogenic mutation on trio whole exome sequencing. One of the fetuses with a normal head size had an OPHN1 mutation with postnatal febrile seizures, and the other had peri-Sylvian polymicrogyria, seizures, and severe developmental delay but no explanatory mutation on whole exome sequencing. CONCLUSION(S): Fetal head size and extracranial prenatal sonographic findings can refine the phenotype and facilitate genetic diagnosis when ganglionic eminence abnormality is diagnosed with MR imaging.Copyright ©

Contains fulltext : 196367.pdf (Publisher’s version ) (Open Access), OBJECTIVE: Comprehensive clinical characterization of congenital titinopathy to facilitate diagnosis and management of this important emerging disorder. METHODS: Using massively parallel sequencing we identified 30 patients from 27 families with 2 pathogenic nonsense, frameshift and/or splice site TTN mutations in trans. We then undertook a detailed analysis of the clinical, histopathological and imaging features of these patients. RESULTS: All patients had prenatal or early onset hypotonia and/or congenital contractures. None had ophthalmoplegia. Scoliosis and respiratory insufficiency typically developed early and progressed rapidly, whereas limb weakness was often slowly progressive, and usually did not prevent independent walking. Cardiac involvement was present in 46% of patients. Relatives of 2 patients had dilated cardiomyopathy. Creatine kinase levels were normal to moderately elevated. Increased fiber size variation, internalized nuclei and cores were common histopathological abnormalities. Cap-like regions, whorled or ring fibers, and mitochondrial accumulations were also observed. Muscle magnetic resonance imaging showed gluteal, hamstring and calf muscle involvement. Western blot analysis showed a near-normal sized titin protein in all samples. The presence of 2 mutations predicted to impact both N2BA and N2B cardiac isoforms appeared to be associated with greatest risk of cardiac involvement. One-third of patients had 1 mutation predicted to impact exons present in fetal skeletal muscle, but not included within the mature skeletal muscle isoform transcript. This strongly suggests developmental isoforms are involved in the pathogenesis of this congenital/early onset disorder. INTERPRETATION: This detailed clinical reference dataset will greatly facilitate diagnostic confirmation and management of patients, and has provided important insights into disease pathogenesis. Ann Neurol 2018;83:1105-1124.