Abstract
Background: Dysferlinopathies represent a group of limb girdle or distal muscular dystrophies with an autosomal-recessive inheritance pattern resulting from the presence of pathogenic variants in the dysferlin gene (DYSF).
Objective: In this work, we describe a population from a small city in Brazil carrying the c.5979dupA pathogenic variant of DYSF responsible for limb girdle muscular dystrophy type 2R and distal muscular dystrophy.
Methods: Genotyping analyses were performed by qPCR using customized probe complementary to the region with the duplication under analysis in the DYSF.
Results: A total of 104 individuals were examined. c.5979dupA was identified in 48 (46.15%) individuals. Twenty-three (22%) were homozygotes, among whom 13 (56.5%) were female. A total of 91.3% (21) of homozygous individuals had a positive family history, and seven (30.4%) reported consanguineous marriages. Twenty-five (24%) individuals were heterozygous (25.8±16 years) for the same variant, among whom 15 (60%) were female. The mean CK level was 697 IU for homozygotes, 140.5 IU for heterozygotes and 176 IU for wild-type homo-zygotes. The weakness distribution pattern showed 17.3% of individuals with a proximal pattern, 13% with a distal pattern and 69.6% with a mixed pattern. Fatigue was present in 15 homozygotes and one heterozygote.
Conclusion: The high prevalence of this variant in individuals from this small community can be explained by a possible founder effect associated with historical, geographical and cultural aspects.
Graphical Abstract
[http://dx.doi.org/10.1002/humu.9355] [PMID: 16010686]
[http://dx.doi.org/10.1016/S0002-9440(10)65354-0] [PMID: 10233840]
[http://dx.doi.org/10.1038/1689] [PMID: 9731527]
[http://dx.doi.org/10.1212/CON.0000000000001178] [PMID: 36537976]
[http://dx.doi.org/10.1016/j.nmd.2018.05.007] [PMID: 30055862]
[http://dx.doi.org/10.1002/1531-8249(200101)49:1<130:AID-ANA22>3.0.CO;2-0] [PMID: 11198284]
[http://dx.doi.org/10.1093/brain/109.1.31] [PMID: 3942856]
[http://dx.doi.org/10.1212/NXG.0000000000000089] [PMID: 27602406]
[http://dx.doi.org/10.1111/cge.14216] [PMID: 36029111]
[http://dx.doi.org/10.1093/brain/123.6.1229] [PMID: 10825360]
[http://dx.doi.org/10.1016/j.nmd.2007.07.010] [PMID: 17825554]
[http://dx.doi.org/10.1590/0004-282x20170151] [PMID: 29236822]
[http://dx.doi.org/10.1159/000369343] [PMID: 25532075]
[http://dx.doi.org/10.1186/s12913-017-2267-3] [PMID: 28464869]
[http://dx.doi.org/10.1038/s41598-020-72366-z] [PMID: 32968083]
[http://dx.doi.org/10.1002/ajhb.22328] [PMID: 23042425]
[http://dx.doi.org/10.1590/S1415-47572010005000020] [PMID: 21637472]
[PMID: 24277254]
[http://dx.doi.org/10.1111/j.1469-1809.2009.00507.x] [PMID: 19344448]
[http://dx.doi.org/10.1016/S0960-8966(00)00143-7] [PMID: 11053681]
[http://dx.doi.org/10.1016/S0960-8966(03)00133-0] [PMID: 14678801]
[http://dx.doi.org/10.3389/fneur.2020.540098] [PMID: 33613410]
[http://dx.doi.org/10.1002/humu.20910] [PMID: 18853459]
[http://dx.doi.org/10.1016/j.nmd.2007.08.009] [PMID: 17897828]
[http://dx.doi.org/10.1002/acn3.649] [PMID: 30564623]
[http://dx.doi.org/10.1590/S0103-20702009000200011]