Microcephaly, growth restriction, and increased sister chromatid exchange (MGRISCE) is characterized by prenatal onset growth restriction and microcephaly. Diagnostically, a hallmark feature is the presence of increased sister chromatid exchanges on cytogenetic testing. MGRISCE1, caused by biallelic mutations in BLM, is known as Bloom syndrome [DS:H01346]. Recently, MGRISCE2, caused by mutations in TOP3A, has been reported. TOP3A encodes topoisomerase III alpha, which binds to BLM as part of the BTRR complex, and promotes dissolution of double Holliday junctions arising during homologous recombination.
Category
Congenital malformation
Brite
Human diseases in ICD-11 classification [BR:br08403]
20 Developmental anomalies
Multiple developmental anomalies or syndromes
LD20 Syndromes with central nervous system anomalies as a major feature
H02492 Microcephaly, growth restriction, and increased sister chromatid exchange
Pathway-based classification of diseases [BR:br08402]
Replication and repair
nt06506 Double-strand break repair
H02492 Microcephaly, growth restriction, and increased sister chromatid exchange
Martin CA, Sarlos K, Logan CV, Thakur RS, Parry DA, Bizard AH, Leitch A, Cleal L, Ali NS, Al-Owain MA, Allen W, Altmuller J, Aza-Carmona M, Barakat BAY, Barraza-Garcia J, Begtrup A, Bogliolo M, Cho MT, Cruz-Rojo J, Dhahrabi HAM, Elcioglu NH, Gorman GS, Jobling R, Kesterton I, Kishita Y, Kohda M, Le Quesne Stabej P, Malallah AJ, Nurnberg P, Ohtake A, Okazaki Y, Pujol R, Ramirez MJ, Revah-Politi A, Shimura M, Stevens P, Taylor RW, Turner L, Williams H, Wilson C, Yigit G, Zahavich L, Alkuraya FS, Surralles J, Iglesias A, Murayama K, Wollnik B, Dattani M, Heath KE, Hickson ID, Jackson AP
Title
Mutations in TOP3A Cause a Bloom Syndrome-like Disorder.
Autosomal-inherited progressive external ophthalmoplegia (PEO) is an adult-onset disease characterized by the accumulation of multiple mitochondrial DNA (mtDNA) deletions in post-mitotic tissues. Mutations in six different genes have been described to cause the autosomal dominant PEO (PEOA). Conversely, the autosomal recessive PEO (PEOB) has only been associated with mutations in POLG1. Recently, mutations in RNASEH1, TK2, and DGUOK has been identified.
Category
Nervous system disease
Brite
Human diseases in ICD-11 classification [BR:br08403]
09 Diseases of the visual system
Strabismus or ocular motility disorders
9C82 Disorders of extraocular muscles
H01395 Autosomal recessive progressive external ophthalmoplegia
Pathway-based classification of diseases [BR:br08402]
Replication and repair
nt06506 Double-strand break repair
H01395 Autosomal recessive progressive external ophthalmoplegia
Reyes A, Melchionda L, Nasca A, Carrara F, Lamantea E, Zanolini A, Lamperti C, Fang M, Zhang J, Ronchi D, Bonato S, Fagiolari G, Moggio M, Ghezzi D, Zeviani M
Title
RNASEH1 Mutations Impair mtDNA Replication and Cause Adult-Onset Mitochondrial Encephalomyopathy.
Ronchi D, Garone C, Bordoni A, Gutierrez Rios P, Calvo SE, Ripolone M, Ranieri M, Rizzuti M, Villa L, Magri F, Corti S, Bresolin N, Mootha VK, Moggio M, DiMauro S, Comi GP, Sciacco M
Title
Next-generation sequencing reveals DGUOK mutations in adult patients with mitochondrial DNA multiple deletions.
Nicholls TJ, Nadalutti CA, Motori E, Sommerville EW, Gorman GS, Basu S, Hoberg E, Turnbull DM, Chinnery PF, Larsson NG, Larsson E, Falkenberg M, Taylor RW, Griffith JD, Gustafsson CM
Title
Topoisomerase 3alpha Is Required for Decatenation and Segregation of Human mtDNA.
Shintaku J, Pernice WM, Eyaid W, Gc JB, Brown ZP, Juanola-Falgarona M, Torres-Torronteras J, Sommerville EW, Hellebrekers DM, Blakely EL, Donaldson A, van de Laar I, Leu CS, Marti R, Frank J, Tanji K, Koolen DA, Rodenburg RJ, Chinnery PF, Smeets HJM, Gorman GS, Bonnen PE, Taylor RW, Hirano M
Title
RRM1 variants cause a mitochondrial DNA maintenance disorder via impaired de novo nucleotide synthesis.
