Progressive Deafness-Dystonia due to SERAC1 Mutations: A Study of 67 cases

• Main Author: Maas, RR
• Publication Date: 2017
• Other Authors: Iwanicka-Pronicka, K, Kalkan Ucar, S, Alhaddad, B, AlSayed, M, Al-Owain, MA, Al-Zaidan, HI, Balasubramaniam, S, Barić, I, Bubshait, DK, Burlina, A, Christodoulou, J, Chung, WK, Colombo, R, Darin, N, Freisinger, P, Garcia Silva, MT, Grunewald, S, Haack, TB, van Hasselt, PM, Hikmat, O, Hörster, F, Isohanni, P, Ramzan, K, Kovacs-Nagy, R, Krumina, Z, Martin-Hernandez, E, Mayr, JA, McClean, P, De Meirleir, L, Naess, K, Ngu, LH, Pajdowska, M, Rahman, S, Riordan, G, Riley, L, Roeben, B, Rutsch, F, Santer, R, Schiff, M, Seders, M, Sequeira, S, Sperl, W, Staufner, C, Synofzik, M, Taylor, RW, Trubicka, J, Tsiakas, K, Unal, O, Wassmer, E, Wedatilake, Y, Wolff, T, Prokisch, H, Morava, E, Pronicka, E, Wevers, RA, de Brouwer, AP, Wortmann, SB
• Format: Article
• Language: eng
• Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Download full: http://hdl.handle.net/10400.17/3195
• topic: Adolescent; Adult; Amino Acid Sequence; Carboxylic Ester Hydrolases; Child; Child, Preschool; Cohort Studies; Deaf-Blind Disorders; Dystonia; Female; Humans; Infant; Infant, Newborn; Intellectual Disability; Male; Mutation; Optic Atrophy; Young Adult; Disease Progression; HDE MTB

OBJECTIVE: 3-Methylglutaconic aciduria, dystonia-deafness, hepatopathy, encephalopathy, Leigh-like syndrome (MEGDHEL) syndrome is caused by biallelic variants in SERAC1. METHODS: This multicenter study addressed the course of disease for each organ system. Metabolic, neuroradiological, and genetic findings are reported. RESULTS: Sixty-seven individuals (39 previously unreported) from 59 families were included (age range = 5 days-33.4 years, median age = 9 years). A total of 41 different SERAC1 variants were identified, including 20 that have not been reported before. With the exception of 2 families with a milder phenotype, all affected individuals showed a strikingly homogeneous phenotype and time course. Severe, reversible neonatal liver dysfunction and hypoglycemia were seen in >40% of all cases. Starting at a median age of 6 months, muscular hypotonia (91%) was seen, followed by progressive spasticity (82%, median onset = 15 months) and dystonia (82%, 18 months). The majority of affected individuals never learned to walk (68%). Seventy-nine percent suffered hearing loss, 58% never learned to speak, and nearly all had significant intellectual disability (88%). Magnetic resonance imaging features were accordingly homogenous, with bilateral basal ganglia involvement (98%); the characteristic "putaminal eye" was seen in 53%. The urinary marker 3-methylglutaconic aciduria was present in virtually all patients (98%). Supportive treatment focused on spasticity and drooling, and was effective in the individuals treated; hearing aids or cochlear implants did not improve communication skills. INTERPRETATION: MEGDHEL syndrome is a progressive deafness-dystonia syndrome with frequent and reversible neonatal liver involvement and a strikingly homogenous course of disease. Ann Neurol 2017;82:1004-1015