Merosin-deficient congenital muscle dystrophy type 1a (MDC1a), or LAMA2 muscular dystrophy (LAMA2-MD) is a severe autosomal recessive form of muscular dystrophy that is caused by homozygous or compound heterozygous mutations in the laminin alpha 2 (LAMA-2) gene. Many different LAMA-2 mutations have been reported. In most cases, MDC1a is diagnosed within the first year of life, and is characterized by hypotonia, delayed motor development and white matter abnormalities. Currently, no efficient treatment is available for this patient group. Generally, MDC1a patients with mutations causing a premature stop codon are most severely affected (early onset LAMA2-MD) and patients with missense mutations are generally affected more mild affected and more late-onset (late onset LAMA2-MD). However, large variation in disease severity and clinical course is observed, even between individuals with the same mutation, e.g. the LAMA2 c.5562+5G>C mutation, which is frequently observed in Dutch MDC1a patients. This study aims to isolate and culture fibroblasts and myogenic stem cells called mesoangioblasts from the skin and muscle biopsies of adult LAMA2 mutation carriers to explore if genetic correction of LAMA2 mutations using CRISPR-Cas9 can be achieved and subsequently assess the effect in vitro, as a first step towards therapy development.

Inclusion Criteria:

• LAMA2 mutation carriers:
• Age >18 years
• Heterozygous or homozygous LAMA2 c.5562+5G>C mutation
• Written informed consent

Controls:

• Written informed consent
• Age >18 years
• No muscular dystrophy or other disease known to affect muscle morphology or function

Exclusion Criteria:

• MDC1a patients and controls:
• No informed consent
• Use of anti-coagulants, anti-thrombotics and other medication influencing coagulation
• Have a weekly alcohol intake of ≥ 35 units (men) or ≥ 24 units (women)
• Current history of drug abuse
• A history of strokes
• Significant concurrent illness
• Ongoing participation in other clinical trials
• Major surgery within 4 weeks of the visit
• Pregnant or lactating women
• Patients unable and/or unwilling to comply with treatment and study instructions
• Any other factor that in the opinion of the investigator excludes the patient from the study

The study will only include patients/controls living in The Netherlands