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Disease Profile

Congenital muscular dystrophy type 1A

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
1-9 / 1 000 000

331 - 2,979

US Estimated

1-9 / 1 000 000

514 - 4,622

Europe Estimated

Age of onset

Neonatal

ICD-10

G71.2

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

Merosin-negative congenital muscular dystrophy; Merosin-deficient congenital muscular dystrophy; Muscular dystrophy, congenital, merosin-deficient;

Categories

Congenital and Genetic Diseases; Nervous System Diseases

Summary

Congenital muscular dystrophy type 1A (MDC1A) belongs to a group of neuromuscular disorders that beings at birth or infancy and is characterized mainly by hypotonia, muscle weakness and muscle wasting. Other signs and symptoms include rigidity of the spine; scoliosis; and delayed, limited motor development, with most individuals needing assistive devices for mobility. Respiratory problems, feeding disorders and seizures may also occur. With time, affected individuals may develop an elongated face and ophthalmoplegia disorders (paralysis or weakness in muscles of the eye). Intellectual development is typically normal. The prognosis is poor, as many affected children do not reach adolescence. It is caused by mutations in the LAMA2 gene and is inherited in an autosomal recessive manner. Treatment is generally symptomatic and includes a multidisciplinary approach.[1]

Symptoms

Infants with congenital muscular dystrophy type 1A (MDC1A) typically have poor muscle tone (hypotonia) and muscle weakness at birth. Within weeks after birth, some affected infants may have feeding and respiratory difficulties. Motor development is often delayed and limited. Most affected infants can sit unsupported and some can stand without assistance. Only a few children with MDC1A are eventually able to walk unassisted.[2] Additional signs and symptoms that affected individuals may experience include joint contractures (stiff or "frozen" joints), congenital hip dislocation, scoliosis, and ophthalmoplegia (paralysis or weakness in the muscles of the eye).[2] Affected children may also develop an elongated face. Approximately 20-30% experience seizures.[3] The majority of affected individuals have normal intellectual abilities.[3] The prognosis of this condition is poor, as many affected children do not reach adolescence.[1]

Although most individuals affected with MDC1A have complete deficiency of the merosin protein, a few individuals have only a partial deficiency. Among individuals with a partial deficiency, the severity and age of onset varies greatly.[3] One study reported that approximately 12% of individuals have later onset, slowly progressive weakness.[4]

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Absent muscle fiber merosin
0030091
Congenital muscular dystrophy
0003741
Gastroesophageal reflux
Acid reflux
Acid reflux disease
Heartburn

[ more ]

0002020
Highly elevated creatine kinase
0030234
Hypokinesia
Decreased muscle movement
Decreased spontaneous movement
Decreased spontaneous movements

[ more ]

0002375
Inability to walk
0002540
Increased connective tissue
0009025
Motor delay
0001270
Muscle fiber atrophy
Muscle fiber degeneration
0100295
Myositis
Muscle inflammation
0100614
Respiratory failure
0002878
Weak cry
0001612
30%-79% of people have these symptoms
Abnormal brainstem MRI signal intensity
0012747
Abnormality of the temporomandibular joint
Abnormality of the jaw joint
Deformity of the jaw joint
Malformation of jaw joint

[ more ]

0010754
Aspiration
0002835
Astrocytosis
0002446
Cerebral edema
Swelling of brain
0002181
EMG abnormality
0003457
Facial palsy
Bell's palsy
0010628
Flexion contracture
Flexed joint that cannot be straightened
0001371
Impaired mastication
Chewing difficulties
Chewing difficulty
Difficulty chewing

[ more ]

0005216
Intellectual disability
Mental deficiency
Mental retardation
Mental-retardation
Mental retardation, nonspecific

[ more ]

0001249
Macroglossia
Abnormally large tongue
Increased size of tongue
Large tongue

[ more ]

0000158
Recurrent lower respiratory tract infections
Recurrent chest infections
0002783
5%-29% of people have these symptoms
Abnormality of visual evoked potentials
0000649
Arrhythmia
Abnormal heart rate
Heart rhythm disorders
Irregular heart beat
Irregular heartbeat

[ more ]

0011675
Atelectasis
Partial or complete collapse of part or entire lung
0100750
Cardiomyopathy
Disease of the heart muscle
0001638
Cognitive impairment
Abnormality of cognition
Cognitive abnormality
Cognitive defects
Cognitive deficits
Intellectual impairment
Mental impairment

[ more ]

0100543
Decreased body weight
Decreased weight
Low body weight
Low weight
Weight less than 3rd percentile

[ more ]

0004325
Dysphagia
Poor swallowing
Swallowing difficulties
Swallowing difficulty

[ more ]

0002015
Focal-onset seizure
Seizure affecting one half of brain
0007359
Generalized non-motor (absence) seizure
Brief seizures with staring spells
0002121
Hyperlordosis
Prominent swayback
0003307
Hypoventilation
Slow breathing
Under breathing

[ more ]

0002791
Intercostal muscle weakness
Muscle weakness between ribs
0004878
Myopathic facies
0002058
Neonatal hypotonia
Low muscle tone, in neonatal onset
0001319
Open mouth
Gaped jawed appearance
Gaped mouthed appearance
Slack jawed appearance

[ more ]

0000194
Ophthalmoplegia
Eye muscle paralysis
0000602
Pachygyria
Fewer and broader ridges in brain
0001302
Pontocerebellar atrophy
0006879
Protruding tongue
Prominent tongue
Tongue sticking out of mouth

[ more ]

0010808
Reduced ejection fraction
0012664
Reduced tendon reflexes
0001315
Scoliosis
0002650
Sensorimotor neuropathy
Nerve damage causing decreased feeling and movement
0007141
1%-4% of people have these symptoms
Pulmonary arterial hypertension
Increased blood pressure in blood vessels of lungs
0002092
Percent of people who have these symptoms is not available through HPO
Abnormal cortical gyration
0002536
Areflexia
Absent tendon reflexes
0001284
Autosomal recessive inheritance
0000007
Congenital onset
Symptoms present at birth
0003577
Elevated serum creatine kinase
Elevated blood creatine phosphokinase
Elevated circulating creatine phosphokinase
Elevated creatine kinase
Elevated serum CPK
Elevated serum creatine phosphokinase
High serum creatine kinase
Increased CPK
Increased creatine kinase
Increased creatine phosphokinase
Increased serum CK
Increased serum creatine kinase
Increased serum creatine phosphokinase

[ more ]

Organizations

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Organizations Providing General Support

      Learn more

      These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

      Where to Start

        In-Depth Information

        • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
        • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
        • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
        • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
        • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
        • PubMed is a searchable database of medical literature and lists journal articles that discuss Congenital muscular dystrophy type 1A. Click on the link to view a sample search on this topic.

          References

          1. M. Fardeau. Congenital muscular dystrophy type 1A. Orphanet. April 2009; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=258. Accessed 9/26/2011.
          2. Congenital Muscular Dystrophy. NORD. January 6, 2010; https://www.rarediseases.org/rare-disease-information/rare-diseases/byID/1196/viewAbstract. Accessed 9/26/2011.
          3. Susan Sparks et al. Congenital Muscular Dystrophy Overview. GeneReviews. January 4, 2011; https://www.ncbi.nlm.nih.gov/books/NBK1291/. Accessed 9/26/2011.
          4. K. Jones et al. The expanding phenotype of laminin a2 chain (merosin) abnormalities: case series and review. J Med Genet. October 2001; 38(10):649-657.

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