Prenatal diagnosis of BMD in Morocco: evolution and limits.

The muscular dystrophy is a group of inherited disorders characterized in the most of cases by progressive muscle weakness. The best known are X-linked disorder Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD). BMD is a milder form of the disease with a later age of onset and a slower clinical progression. The DMD gene, located on Xp21, is the largest human gene in the human genome (2.3 Mb). DMD gene consists of 79 exons and codes for dystrophin protein. A 9-year-old boy, who experienced symptoms of the disease, was admitted to the Casablanca University Children's Hospital. The patient, with no known family history of significant muscle disease, was first examined at 4 years of age because of walking difficulties and a limited hands force. Blood tests revealed elevated serum levels of creatine kinase (7.60 U/L). The electromyogram showed myopathic changes, consisting of polyphasic potentials, and the muscular biopsy revealed dystrophic aspect. Analysis of the dystrophin-encoding gene by PCR deletion analysis of the dystrophin gene was performed by multiplex PCR primer sets of Chamberlain and Beggs. The analysis showed a deletion of exons 45 to 49. Mother genetic testing showed the heterozygosis deletion.

Evolution of molecular diagnosis of Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is the commonest of the muscular dystrophies. The DMD gene (DMD) is the biggest human gene and the most common molecular defect in the DMD gene, accounting for approximately 65 % of cases of DMD, is the deletion of one or more exons. The most basic method still in regular use involves multiplex PCR of the exons, known to be most commonly deleted. The multiplex is relatively simple. Quantitative analysis of all exons of the gene and multiplex ligation-dependent probe amplification have brought about an improvement in mutation detection rate, as they will detect all exon scale deletions as well as duplications, widely used to detect exonic and intronic mutations. As a sensitive and discriminative tool, MLPA can be used for prenatal testing. A more recent development in quantitative analysis is the use of oligonucleotide-based array comparative genomic hybridization.

Sickle cell disease with double stroke in a Moroccan family.

The sickle-cell disease is a group of chronic hemolytic diseases which associates three types of injuries: severe anemia, severe infections, and ischemic vaso-occlusive crisis that are secondary to conflicts between small vessels and red blood cells too deformable. Thus, organic various complications may arise. Its prevalence in Europe is estimated to be about 1/150 and reaches 15 % in the Mediterranean areas. Clinical manifestations vary widely from one person to another and from one moment to another. In addition to anemia and bacterial infections, vaso-occlusive crisis may manifest by focal ischemia. In the long term, the VOC may compromise the function of a particular tissue or organ. The transmission is autosomal recessive. The sickle-cell diseases are determined by combinations of two abnormal alleles of beta globin gene including at least one which carries the mutation beta 6 glu-val (Hb S). We report the case of a girl aged 11 years, who presented two strokes in the interval of 8 months, which manifested by a complete right hemiplegia and aphasia confirmed by head CT scan; the electrophoresis of the hemoglobin and the molecular test had confirmed the diagnosis of sickle-cell disease, and we were allowed to spread better reflection on the prevention of stroke, which remains a frequent and serious complication of sickle-cell disease.

Prader-Willi syndrome: Methylation study or fluorescence in situ hybridization first?

Prader-Willi syndrome (PWS) is neurogenetic disorder involving the imprinting mechanism at 15q11-13 region. We report a 4-year-old girl who was referred to our laboratory to be investigated for clinical obesity, mental deficiency and respiratory problems. The patient was born for non-consanguineous and healthy biological parents. After normal pregnancy, the patient was delivered by cesarean section at full term, with a birth weight of 2500 g, and the height and head circumference were unknown. In neonatal stage, she presented severe hypotonia with feeding problems. Her developmental progress was delayed. She walked and developed speech at the age of 3 years. Since the age of 3 years, she presented severe dental problems. Methylation study had confirmed the diagnosis, and for detecting etiology, fluorescence in situ hybridization using probes for small nuclear ribonucleoprotein polypeptide N (SNRPN), which map inside the chromosomal region 15q11-15q13, was necessary to confirm the 15q11-15q13 deletion of paternal chromosome 15, which is the predominant genetic defect in PWS. In conclusion, we report this case with an objective to reinforce the necessity of analysis of DNA methylation within the 15q11-13 region, which is an important tool for the correct diagnosis among children presenting with neonatal hypotonia, mental deficiency and obesity.