Phenotype-genotype analysis of dystrophinopathy caused by duplication mutation in Dystrophin gene in an African patient.
BACKGROUND
The dystrophinopathies, duchenne muscular dystrophy (DMD) and Becker muscular dystrophy are common X-linked genetic myopathies resulting from mutations in the dystrophin gene. Duplication is an uncommon mechanism of mutation occurring in about 5% of DMD cases. The global prevalence of DMD is reported as 1/18,000 males. There is little clinical or epidemiological data on African patients.


OBJECTIVE
To present the genotype-phenotype analysis of dystrophinopathy with an exon 8 through 9 duplication mutation in a patient of African/Ghanaian descent and his asymptomatic mother.


METHODS
Investigations including a biopsy of the vastus lateralis muscle and genetic testing of the patient and his mother.


RESULTS
Genetic testing demonstrated a duplication of exons 8 through 9 of the dystrophin gene in both the patient and his mother. The muscle biopsy of the patient showed partial expression of the dystrophin protein. In the absence of a family history of dystrophinopathy, we hypothesize that this is a sporadic mutation occurring in the grand maternal lineage.


CONCLUSIONS
This case extends the world wide epidemiology of this disease to include the African/Ghanaian population and confirms the vulnerability of the dystrophin gene to recurrent spontaneous mutations at the exon 8 and 9 site.
Neurogenetics Foundation, Cranbury, New Jersey, USA.
L R
LR
Peddareddygari
B H
BH
Pillai
D
D
Nochlin
L R
LR
Sharer
R P
RP
Grewal
D001706:Biopsy; D044383:Black People; D002648:Child; D004252:DNA Mutational Analysis; D016189:Dystrophin / Q000235:genetics*; D005091:Exons / Q000235:genetics; D056726:Genetic Association Studies; D005838:Genotype; D005869:Ghana; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009035:Mothers; D018908:Muscle Weakness / Q000209:etiology; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics* / Q000473:pathology*; D009154:Mutation / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype
D016189:Dystrophin