Genetic tests, including prenatal testing, are available for both confirmed forms. Molecular testing is considered the gold standard of diagnosis.

Testing at pregnancy to determine whether an unborn child is affected is possible if genetic testing in a family has identified a DMPK mutation. This can be done at 10–12 weeks gestation by a procedure called chorionic villus sampling (CVS) that involves removing a tiny piece of the placenta and analyzing DNA from its cells. It can also be done by amniocentesis after 14 weeks gestation by removing a small amount of the amniotic fluid surrounding the baby and analyzing the cells in the fluid. Each of these procedures has a small risk of miscarriage associated with it and those who are interested in learning more should check with their doctor or genetic counselor.

There is also another procedure called preimplantation diagnosis that allows a couple to have a child that is unaffected with the genetic condition in their family. This procedure is experimental and not widely available. Those interested in learning more about this procedure should check with their doctor or genetic counselor.

It is possible to test someone who is at risk for developing DM1 before they are showing symptoms to see whether they inherited an expanded trinucleotide repeat. This is called predictive testing. Predictive testing cannot determine the age of onset that someone will begin to have symptoms, or the course of the disease. If the child is not having symptoms, the testing is not possible with an exception of emancipated minors as a policy.

The diagnosis of oculopharyngeal muscular dystrophy can be done via two methods, a muscle biopsy or a blood draw with genetic testing for GCG trinucleotide expansions in the PABPN1 gene. The genetic blood testing is more common.Additionally, a distinction between OPMD and myasthenia gravis or mitochondrial myopathy must be made, in regards to the differential diagnosis of this condition.

The subtypes of congenital muscular dystrophy have been established through variations in multiple genes. It should be noted that phenotype, as well as, genotype classifications are used to establish the subtypes, in some literature.

One finds that congenital muscular dystrophies can be either autosomal dominant or autosomal recessive in terms of the inheritance pattern, though the latter is much more common

Individuals who suffer from congenital muscular dystrophy fall into one of the following "types":

In terms of the diagnosis of Becker muscular dystrophy symptom development resembles that of Duchenne muscular dystrophy. A physical exam indicates lack of pectoral and upper arm muscles, especially when the disease is unnoticed through the early teen years. Muscle wasting begins in the legs and pelvis, then progresses to the muscles of the shoulders and neck. Calf muscle enlargement (pseudohypertrophy) is quite obvious. Among the exams/tests performed are:

- Muscle biopsy

- Creatine kinase test

- Electromyography (shows that weakness is caused by destruction of muscle tissue rather than by damage to nerves.)

- Genetic testing

The diagnosis of limb-girdle muscular dystrophy can be done via muscle biopsy, which will show the presence of muscular dystrophy, and genetic testing is used to determine which type of muscular dystrophy a patient has. Immunohistochemical dystrophin tests can indicate a decrease in dystrophin detected in sarcoglycanopathies. In terms of sarcoglycan deficiency there can be variance (if α-sarcoglycan and γ-sarcoglycan are not present then there's a mutation in LGMD2D).

The 2014 "Evidence-based guideline summary: Diagnosis and treatment of limb-girdle and distal dystrophies" indicates that individuals suspected of having the inherited disorder should have genetic testing. Other tests/analysis are:

- High CK levels(x10-150 times normal)

- MRI can indicate different types of LGMD.

- EMG can confirm the myopathic characteristic of the disease.

- Electrocardiography (cardiac arrhythmias in LGMD1B can occur)

For the diagnosis of congenital muscular dystrophy, the following tests/exams are done:

- Lab study (CK levels)

- MRI (of muscle, and/or brain)

- EMG

- Genetic testing

The diagnosis of muscular dystrophy is based on the results of muscle biopsy, increased creatine phosphokinase (CpK3), electromyography, and genetic testing. A physical examination and the patient's medical history will help the doctor determine the type of muscular dystrophy. Specific muscle groups are affected by different types of muscular dystrophy.

Other tests that can be done are chest X-ray, echocardiogram, CT scan, and magnetic resonance image scan, which via a magnetic field can produce images whose detail helps diagnose muscular dystrophy.

The progression of Becker muscular dystrophy is highly variable—much more so than Duchenne muscular dystrophy. There is also a form that may be considered as an intermediate between Duchenne and Becker MD (mild DMD or severe BMD).

Severity of the disease may be indicated by age of patient at the onset of the disease. One study showed that there may be two distinct patterns of progression in Becker muscular dystrophy. Onset at around age 7 to 8 years of age shows more cardiac involvement and trouble climbing stairs by age 20, if onset is around age 12, there is less cardiac involvement.

The quality of life for patients with Becker muscular dystrophy can be impacted by the symptoms of the disorder. But with assistive devices, independence can be maintained. People affected by Becker muscular dystrophy can still maintain active lifestyles.

The "LGMD1" family is autosomal dominant, and the "LGMD2" family is autosomal recessive. Limb-girdle muscular dystrophy is explained in terms of gene, locus, OMIM and type as follows:

In terms of diagnosis of Fukuyama congenital muscular dystrophy, serum creatine kinase concentration and muscle biopsies can be obtained to help determine if the individual has FMCD. FKTN molecular genetic testing is used to determine a mutation in the FKTN gene after a serum creatine kinase concentration, muscle biopsies, and/or MRI imaging have presented abnormalities indicative of FCMD, the presence of the symptoms indicates Fukuyama congenital muscular dystrophy. The available genetic test include:

- Linkage analysis

- Deletion analysis

- Sequence analysis - exons

- Sequence analysis - entire coding region

In terms of the diagnosis of Ullrich congenital muscular dystrophy upon inspection follicular hyperkeratosis, may be a dermatological indicator, additionally also serum creatine kinase may be mildly above normal. Other exams/methods to ascertain if the individual has Ullrich congenital muscular dystrophy are:

Fukuyama congenital muscular dystrophy has a poor prognosis. Most children with FCMD reach a maximum mobility at sitting upright and sliding. Due to the compounded effects of continually worsening heart problems, impaired mental development, problems swallowing and additional complications, children with FCMD rarely live through adolescence, the disorder proves fatal by age 20.

The diagnosis of Emery–Dreifuss muscular dystrophy can be established via single-gene testing or genomic testing, and clinically diagnosed via the following exams/methods:

In terms of possible research for Ullrich congenital muscular dystrophy one source indicates that cyclosporine A might be of benefit to individuals with this CMD type.

According to a review by Bernardi, et al., cyclosporin A (CsA) used to treat collagen VI muscular dystrophies demonstrates a normalization of mitochondrial reaction to rotenone.

It is not necessary to biopsy an ocular muscle to demonstrate histopathologic abnormalities. Cross-section of muscle fibers stained with Gömöri trichrome stain is viewed using light microscopy. In muscle fibers containing high ratios of the mutated mitochondria, there is a higher concentration of mitochondria. This gives these fibers a darker red color, causing the overall appearance of the biopsy to be described as "ragged red fibers. Abnormalities may also be demonstrated in muscle biopsy samples using other histochemical studies such as mitochondrial enzyme stains, by electron microscopy, biochemical analyses of the muscle tissue (ie electron transport chain enzyme activities), and by analysis of muscle mitochondrial DNA. "

A neuro-ophthalmologist is usually involved in the diagnosis and management of KSS. An individual should be suspected of having KSS based upon clinical exam findings. Suspicion for myopathies should be increased in patients whose ophthalmoplegia does not match a particular set of cranial nerve palsies (oculomotor nerve palsy, fourth nerve palsy, sixth nerve palsy). Initially, imaging studies are often performed to rule out more common pathologies. Diagnosis may be confirmed with muscle biopsy, and may be supplemented with PCR determination of mtDNA mutations.

Currently no cure or specific treatment exists to eliminate the symptoms or stop the disease progression. A consistent diet planned with the help of a dietitian along with exercises taught by a speech therapist can assist with mild symptoms of dysphagia. Surgical intervention can also help temporarily manage symptoms related to the ptosis and dysphagia. Cutting one of the throat muscles internally, an operation called cricopharyngeal myotomy, can be one way to ease symptoms in more severe cases.

Physical therapy and specifically designed exercises may assist with proximal limb weakness, though there is still no current definitive data showing it will stop the progress of the disease. Many of those affected with the proximal limb weakness will eventually require assistive devices such as a wheelchair. As with all surgical procedures, they come with many risk factors. As the dysphagia becomes more severe, patients become malnourished, lose significant weight, become dehydrated and suffer from repeated incidents of aspiration pneumonia. These last two are often the cause of death.

Prognosis depends on the individual form of MD. In some cases, a person with a muscle disease will get progressively weaker to the extent that it shortens lifespan due to heart and breathing complications. However, some of the muscle diseases do not affect life expectancy at all, and ongoing research is attempting to find cures and treatments to slow muscle weakness.

The types of Emery–Dreifuss muscular dystrophy are distinguished by their pattern of inheritance: X-linked, autosomal dominant, and autosomal recessive.

- Autosomal dominant "Emery–Dreifuss muscular dystrophy" individuals experience heart problems with weakness (and wasting) of skeletal muscles and Achilles tendon contractures.

- X-linked "Emery–Dreifuss muscular dystrophy" is the result of the EMD gene, with cardiac involvement and some mental retardation.

- Autosomal recessive individuals with this type of the disorder demonstrate cardiac issues, such as arrhythmia. Individuals who acquire EDMD via the autosomal recessive route have an incidence of 1 in 300,000.

Some cases of myotonia congenita do not require treatment, or it is determined that the risks of the medication outweigh the benefits. If necessary, however, symptoms of the disorder may be relieved with quinine, phenytoin, carbamazepine, mexiletine and other anticonvulsant drugs. Physical therapy and other rehabilitative measures may also be used to help muscle function. Genetic counseling is available.

The extent of retinal damage is assessed by fluorescent angiography, retinal scanning and optical coherence tomography; electrophysiological examinations such as electroretinography (ERG) or multifocal electroretinography (mfERG) may also be used.

Anomalies of the hair shaft caused by ectodermal dysplasia should be ruled out. Mutations in the CDH3 gene can also appear in EEM syndrome.

Corneal transplant is not needed except in very severe and late cases.

Light sensitivity may be overcome by wearing tinted glassess.

In some cases, signs and symptoms of infantile neuroaxonal dystrophy first appear later in childhood or during the teenage years and progress more slowly.

Children with infantile neuroaxonal dystrophy experience progressive difficulties with movement. Generally they have muscles that are at first weak and "floppy" (hypotonic), and then gradually become very stiff (spastic). Eventually, affected children lose the ability to move independently. Lack of muscle strength causes difficulty with feeding and breathing problems that can lead to frequent infections, such as pneumonia. Seizures occur in some affected children.

Rapid, involuntary eye movements (nystagmus), eyes that do not look in the same direction (strabismus), and vision loss due to deterioration (atrophy) of the optic nerve are characteristic of infantile neuroaxonal dystrophy. Hearing loss may also develop. Children with this disorder experience progressive deterioration of cognitive functions (dementia), and eventually lose awareness of their surroundings.

Infantile neuroaxonal dystrophy is characterized by the development of swellings called spheroid bodies in the axons, the fibers that extend from nerve cells (neurons) and transmit impulses to muscles and other neurons. A part of the brain called the cerebellum, which helps to control movements, may also be damaged. In some individuals with infantile neuroaxonal dystrophy, abnormal amounts of iron accumulate in a specific region of the brain called the basal ganglia.