First detection of the hemizygote frameshift variant of the DMD gene in a 13-year-old patient affected by dystrophinopathy (Duchenne DMD and Becker BMD) at Saint Camille Hospital of Ouagadougou, Burkina Faso: Case report

Abstract

Genetic diseases are poorly reported in sub-Saharan Africa, especially in Burkina Faso. The reasons for this reality are multifactorial including, the difficulty of diagnostic confirmation, financial accessibility and even the difficulty with referral of cases by medical staff. Genetic diseases, although relatively rare, exist in families and deserve special attention in our paraclinical assessments. Few cases can be diagnosed in sub-Saharan Africa. The clinical case we are reporting here is a dystrophynopathy by mutation of the Duchenne muscular dystrophy (DMD) gene. This is the first confirmed detection of a frameshift mutation in the DMD gene in a boy received at Saint Camille Hospital in Ouagadougou, Burkina Faso. This is a 13-year-old MR boy, from a family of four siblings, all male, from the eastern region of Burkina Faso. The boy had a clinical picture of myopathy with difficulty in walking, frequent falls, myogenic syndrome with stool sign, Gowers sign and scapula alata, all leading to a suspicion of dystrophinopathy with a request for genetic analysis. The DMD gene responsible for the disease is located on the X chromosome (Xp21.2-p21.1). The study of the dystrophin gene (DMD) was done using three methods, namely MLPA, high throughput sequencing and Sanger sequencing. The results led to the identification of a frameshift mutation of exon 71 in the DMD gene: it is a hemizygotic variant with ribosomal shift of the DMD gene NM_004006.2 (DMD): c.10258del p.(Ser3420Leufs*25). This clinical case led for the first time in Burkina Faso to the confirmed diagnosis of hereditary muscular dystrophy resulting from a mutation with a frameshift in exon 71 of the DMD gene in the hemizygotic state in a 13-year-old boy, a student and the eldest sibling of 4 boys, three of whom have myopathy. Key words: Mutation, Duchenne muscular dystrophy (DMD) gene, dystrophinopathy, duchenne versus becker, case report.