BRAT1 mutations present with a spectrum of clinical severity
- PMID: 27282546
- PMCID: PMC5532882
- DOI: 10.1002/ajmg.a.37783
BRAT1 mutations present with a spectrum of clinical severity
Abstract
Mutations in BRAT1, encoding BRCA1-associated ATM activator 1, are associated with a severe phenotype known as rigidity and multifocal seizure syndrome, lethal neonatal (RMFSL; OMIM # 614498), characterized by intractable seizures, hypertonia, autonomic instability, and early death. We expand the phenotypic spectrum of BRAT1 related disorders by reporting on four individuals with various BRAT1 mutations resulting in clinical severity that is either mild or moderate compared to the severe phenotype seen in RMFSL. Representing mild severity are three individuals (Patients 1-3), who are girls (including two sisters, Patients 1-2) between 4 and 10 years old, with subtle dysmorphisms, intellectual disability, ataxia or dyspraxia, and cerebellar atrophy on brain MRI; additionally, Patient 3 has well-controlled epilepsy and microcephaly. Representing moderate severity is a 15-month-old boy (Patient 4) with severe global developmental delay, refractory epilepsy, microcephaly, spasticity, hyperkinetic movements, dysautonomia, and chronic lung disease. In contrast to RMFSL, his seizure onset occurred later at 4 months of age, and he is still alive. All four of the individuals have compound heterozygous BRAT1 mutations discovered via whole exome sequencing: c.638dupA (p.Val214Glyfs*189); c.803+1G>C (splice site mutation) in Patients 1-2; c.638dupA (p.Val214Glyfs*189); c.419T>C (p.Leu140Pro) in Patient 3; and c.171delG (p.Glu57Aspfs*7); c.419T>C (p.Leu140Pro) in Patient 4. Only the c.638dupA (p.Val214Glyfs*189) mutation has been previously reported in association with RMFSL. These patients illustrate that, compared with RMFSL, BRAT1 mutations can result in both moderately severe presentations evident by later-onset epilepsy and survival past infancy, as well as milder presentations that include intellectual disability, ataxia/dyspraxia, and cerebellar atrophy. © 2016 Wiley Periodicals, Inc.
Keywords: BRAT1; RMFSL; cerebellar atrophy; clinical severity; epilepsy; intellectual disability.
© 2016 Wiley Periodicals, Inc.
Conflict of interest statement
Dr. Davis and Ms. Shahmirzadi are paid employees of Ambry Genetics. David Miller and Tim Yu serve as part-time consultant to Claritas Genomics, a provider of genetic testing services (non-equity professional services agreement).
References
-
- Antoniou A, Pharoah PDP, Narod S, Risch HA, Eyfjord JE, Hopper JL, Loman N, Olsson H, Johannsson O, Borg A, Pasini B, Radice P, Manoukian S, Eccles DM, Tang N, Olah E, Anton-Culver H, Warner E, Lubinski J, Gronwald J, Gorski B, Tulinius H, Thorlacius S, Eerola H, Nevanlinna H, Syrjäkoski K, Kallioniemi O-P, Thompson D, Evans C, Peto J, Lalloo F, Evans DG, Easton DF. Average risks of breast and ovarian cancer associated with BRCA1 or BRCA2 mutations detected in case Series unselected for family history: a combined analysis of 22 studies. Am J Hum Genet. 2003;72:1117–1130. - PMC - PubMed
-
- Easton DF. Cancer risks in A-T heterozygotes. Int J Radiat Biol. 1994;66:S177–182. - PubMed
-
- Farwell KD, Shahmirzadi L, El-Khechen D, Powis Z, Chao EC, Tippin Davis B, Baxter RM, Zeng W, Mroske C, Parra MC, Gandomi SK, Lu I, Li X, Lu H, Lu H-M, Salvador D, Ruble D, Lao M, Fischbach S, Wen J, Lee S, Elliott A, Dunlop CLM, Tang S. Enhanced utility of family-centered diagnostic exome sequencing with inheritance model-based analysis: results from 500 unselected families with undiagnosed genetic conditions. Genet Med. 2015;17:578–586. - PubMed
-
- Gandomi SK, Farwell Gonzalez KD, Parra M, Shahmirzadi L, Mancuso J, Pichurin P, Temme R, Dugan S, Zeng W, Tang S. Diagnostic exome sequencing identifies two novel IQSEC2 mutations associated with X-linked intellectual disability with seizures: implications for genetic counseling and clinical diagnosis. J Genet Couns. 2014;23:289–298. - PubMed
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources
Molecular Biology Databases
Research Materials
Miscellaneous
