Gut Interactions with Brain and Environment in Children; First International Symposium on Pediatric Neurogastroenterology Capri, Italy, September 18-20, 1997
Gastrointestinal disorders, related to muscular dystrophies, are not well studied. These disturbances however can be prominent in some cases. Muscular dystrophies are an heterogeneous group of disorders characterized by a progressive distruction of striated muscular fibers.
The most common is the Duchenne Muscular Dystrophy (DMD), a sex-linked recessive disorder. The gene is localized on Xp21. The genetic product is called dystrophin, a structural protein virtually absent in all muscular striated fibers.
Becker Muscular Dystrophy (BMD) is allelic to DMD. The genetic product is always the dystrophin that is functionally inferior to the normal protein. Quantities in the muscle are variable oscillating between 20 to 100% of the normal values.
Emery Dreyfuss Muscular Dystrophy (EDMD) is a late onset form with a prominent distribution in the humeral-peroneal muscles and a progressive atrophy. Myocardial involvement is preminent and necessitates the use of a pace-maker. The disease is X-linked. A novel gene STA is considered a putative gene.
In DMD dysphagia, constipation and fecal impaction heve been described. Abdominal pain, diarrhoea, vomiting, abdominal distention and acute gastric dilatation have been observed. Histologically edema, atrophy and fibrosis of smooth muscles from distal oesophagus, stomach, small bowel and colon have been described.
Myotonic dystrophy (DM) is a genetic disease with an autosomal dominant (AD) type of trasmission. It is one of the most prevalent AD type of defects and a slowly progressive multisystemic disorder, myotonia, muscular atrophy, cataracts and endocrin dysfunction. The most severe congenital form is associated with generalized hypotonia mental retardation and high neonatal mortality. This form is, almost always, maternally trasmitted. The gene has beeen mapped on chromosome 19q13.3 and an expanded CTA repeat in 3′ untraslated region of the gene has been identified as the casual mutation. Genetic anticipation is now well known. Up of 50% of the patient with DM (Chiu) can have gastrointestinal symptoms with dysphagia, regurgitation, heartburn, asymmetric pharyngeal contraction. Peristaltic abnormalities can be documented radiologically. Esophageal symptoms can be prominent even when muscular signs are absent. Vomiting, constipation and diarrhoea have been reported. They are related to pathological findings consisting in atrophic abnormalities of striated pharyngeal and esophageal muscles. Dystrophy and fatty infiltration of the smooth fibers of the stomach, small bowel and colon have been described.
Facioscapulo-homeral muscular dystrophy (FSHD) is an AD disorder with a progressive weakness of face, shoulder and upper extremities. The gene responsible is assigned to chromosome 4q36 associated with a short EcoRI fragment ranging from 14 to 28 Kb in affected members either sporadic or familial. A genetic eterogeneity is possible and the molecular mechanism unknown. The disease is evident in adult age.
Congenital muscular dystrophies (CMD) are a group of genetic disorders with a common phenotipic aspect of a more or less marked muscular weakness and hypotonia from birth or from the first months of the life. The histological picture shows dystrophic muscular findings with or without cerebral involvement. Different types have been described, one, so called classical congenital muscular dystrophy (CCMD) is usually merosin positive. In merosin negative type the neurological involvement is usually severe with abnormal cerebral imaging. The genetic defect has been localized on chromosome 9q31-33.
The Walker-Warburg syndrome (WWS) is a severe CMD with severe cerebral and ocular abnormalities. It is possible that in this form a defect of laminine 2 and adhalin is present. Clinical and pathologic involvement of smooth muscles of the GI tract are not considered in literature.
In conclusion studies regarding a different involvement of striated and smooth muscles of the pharynx or GI motility could help to obtain a better knowledge of this type of disorders that are possibly overlooked and indicate a more efficient therapeutic approach.
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