Treatment for MSS is symptomatic and supportive including physical and occupational therapy, speech therapy, and special education. Cataracts must be removed when vision is impaired, generally in the first decade of life. Hormone replacement therapy is needed if hypogonadism is present.

Treatments are usually based on the individuals symptoms that are displayed. The seizures are controlled with anticonvulsant medication. For the behavior problems, the doctors proscribe to a few medications and behavioral modification routines that involve therapists and other types of therapy. Even if mental retardation is severe, it does not seem to shorten the lifespan of the patient or to get worse with age.

There is no cure for PMD, nor is there a standard course of treatment. Treatment, which is symptomatic and supportive, may include medication for seizures and spasticity. Regular evaluations by physical medicine and rehabilitation, orthopedic, developmental and neurologic specialists should be made to ensure optimal therapy and educational resources. The prognosis for those with Pelizaeus–Merzbacher disease is highly variable, with children with the most severe form (so-called connatal) usually not surviving to adolescence, but survival into the sixth or even seventh decades is possible, especially with attentive care. Genetic counseling should be provided to the family of a child with PMD.

In December 2008, StemCells Inc., a biotech company in Palo Alto, received clearance from the U.S. Food and Drug Administration (FDA) to conduct Phase I clinical trials in PMD to assess the safety of transplanting human neural stem cells as a potential treatment for PMD. The trial was initiated in November 2009 at the University of California, San Francisco (UCSF) Children's Hospital.

Treatment plans will vary depending on the severity of the condition and its evidences in each patient.

Areas that will probably need to be evaluated and assessed include speech, vision, hearing and EEG. Treatment measures may include physical therapy, occupational therapy, Speech therapy, anti-seizure drugs and orthotic devices. Surgery may be needed to assuage spastic motor problems. Various supportive measures such as joint contractures that could prevent complications.

Genetic counseling may also be recommended

No specific treatment is known that would prevent, slow, or reverse HSP. Available therapies mainly consist of symptomatic medical management and promoting physical and emotional well-being. Therapeutics offered to HSP patients include:

- Baclofen – a voluntary muscle relaxant to relax muscles and reduce tone. This can be administered orally or intrathecally. (Studies in HSP )

- Tizanidine – to treat nocturnal or intermittent spasms (studies available )

- Diazepam and clonazepam – to decrease intensity of spasms

- Oxybutynin chloride – an involuntary muscle relaxant and spasmolytic agent, used to reduce spasticity of the bladder in patients with bladder control problems

- Tolterodine tartate – an involuntary muscle relaxant and spasmolytic agent, used to reduce spasticity of the bladder in patients with bladder control problems

- Botulinum toxin – to reduce muscle overactivity (existing studies for HSP patients)

- Antidepressants (such as selective serotonin re-uptake inhibitors, tricyclic antidepressants and monoamine oxidase inhibitors) – for patients experiencing clinical depression

- Physical therapy – to restore and maintain the ability to move; to reduce muscle tone; to maintain or improve range of motion and mobility; to increase strength and coordination; to prevent complications, such as frozen joints, contractures, or bedsores.

There is no known cure available for the Wilson-Turner Syndrome. Instead, treatment options are available to fight individual symptoms. For obesity, a nutritional diet manipulation is combined with an exercise regimen that has a greater energy expenditure than intake. For hypogonadism, testosterone replacement is done. Finally, for gynecomastia, weight loss using similar methods for obesity is prescribed. However, if the individual finds his increased breast tissue psychologically distressing and/or is too severe, reduction mammaplasty is done. Currently, researchers are investigating therapy using antiestrogens and aromatase inhibitors to treat persistent pubertal gynecomastia.

Treatment is supportive.

- The aplastic anemia and immunodeficiency can be treated by bone marrow transplantation.

- Supportive treatment for gastrointestinal complications and infections.

- Genetic counselling.

The treatment of 2-Hydroxyglutaric aciduria is based on seizure control, the prognosis depends on how severe the condition is.

As with all types of ichthyosis, there is no cure but the symptoms can be relieved.

- Moisturizers

- Prevention of overheating

- Eye drops (to prevent the eyes from becoming dried out)

- Systemic Retinoids (isotretinoin and acitretin are very effective, but careful monitoring for toxicity is required. Only severe cases may require intermittent therapy.)

Psychological therapy or support may be required as well.

It has been suggested that a possible method of treatment for histidinemia is through the adoption of a diet that is low in histidine intake. However, the requirement for such dietary restrictions is typically unnecessary for 99% of all cases of histidinemia.

Treatments for ichthyosis often take the form of topical application of creams and emollient oils, in an attempt to hydrate the skin. Creams containing lactic acid have been shown to work exceptionally well in some cases. Application of propylene glycol is another treatment method. Retinoids are used for some conditions.

Exposure to sunlight may improve or worsen the condition. In some cases, excess dead skin sloughs off much better from wet tanned skin after bathing or a swim, although the dry skin might be preferable to the damaging effects of sun exposure.

There can be ocular manifestations of ichthyosis, such as corneal and ocular surface diseases. Vascularizing keratitis, which is more commonly found in congenital keratitis-ichythosis-deafness (KID), may worsen with isotretinoin therapy.

Direct treatment that stimulates the pyruvate dehydrogenase complex (PDC), provides alternative fuels, and prevents acute worsening of the syndrome. However, some correction of acidosis does not reverse all the symptoms. CNS damage is common and limits a full recovery. Ketogenic diets, with high fat and low carbohydrate intake have been used to control or minimize lactic acidosis and anecdotal evidence shows successful control of the disease, slowing progress and often showing rapid improvement. No study has yet been published demonstrating the effectiveness of the ketogenic diet for treatment of PDCD.

There is some evidence that dichloroacetate reduces the inhibitory phosphorylation of pyruvate dehydrogenase complex and thereby activates any residual functioning complex. Resolution of lactic acidosis is observed in patients with E1 alpha enzyme subunit mutations that reduce enzyme stability. However, treatment with dichloroacetate does not improve neurological damage. Oral citrate is often used to treat acidosis.

Unlike Borjeson-Forssman-Lehmann syndrome, a disorder that was determined to be very similar to WTS, the individuals with Wilson–Turner syndrome do not develop cataracts or hypermetropia later in life. By far, the most debilitating part of this disorder is intellectual disability. Many of the other symptoms are more easily managed through hormone treatment, proper diet and exercise, and speech therapy.

Because pachygyria is a structural defect no treatments are currently available other than symptomatic treatments, especially for associated seizures. Another common treatment is a gastrostomy (insertion of a feeding tube) to reduce possible poor nutrition and repeated aspiration pneumonia.

Treatment should be based on assessment by relevant health professionals. For spastic muscles with mild-to-moderate impairment, exercise should be the mainstay of management, and is likely needed to be prescribed by an occupational therapist, physical therapist, accredited exercise physiologist (AEP) or other health professional skilled in neurological rehabilitation.

Muscles with severe spasticity are likely to be more limited in their ability to exercise, and may require help to do this. They may require additional interventions, to manage the greater neurological impairment and also the greater secondary complications. These secondary complications involve the development of contractures, deformity and postural asymmetries. Interventions may include icing, serial casting, sustained stretching, inhibitory pressure and medical interventions. Treatment should be done with firm and constant manual contact positioned over nonspastic areas to avoid stimulating the spastic muscle(s). Alternatively, rehabilitation robotics can be used to provide high volumes of passive or assisted movement, depending on the individual's requirements; this form of therapy can be useful if therapists are at a premium, and has been found effective at reducing spasticity in patients suffering from stroke. For muscles that lack any volitional control, such as after complete spinal cord injury, exercise may be assisted, and may require equipment, such as using a standing frame to sustain a standing position. A general treatment guideline can be followed that involves:

- The initial focus on first activating contraction of antagonist muscles to provide reciprocal inhibition and lengthen spastic muscles

- Reciprocal actions are attempted. Agonist contractions are performed first in small ranges progressing to larger arcs of movement

- Highly stressful activities be minimized early in training

- Functional skills are targeted for training

- Patients and family/caregivers should be educated about the importance of maintaining range of motion and doing daily exercises

Medical interventions may include such medications as baclofen, diazepam, dantrolene, or clonazepam. Phenol injections can be used, or botulinum toxin injections into the muscle belly, to attempt to dampen the signals between nerve and muscle. The effectiveness of medications vary between individuals, and vary based on location of the upper motor neuron lesion (in the brain or the spinal cord). Medications are commonly used for spastic movement disorders, but research has not shown functional benefit for some drugs. Some studies have shown that medications have been effective in decreasing spasticity, but that this has not been accompanied by functional benefits. Surgery could be required for a tendon release in the case of a severe muscle imbalance leading to contracture. In spastic CP, selective dorsal rhizotomy has also been used to decrease muscle overactivity.

Incorporating hydrotherapy in the treatment program may help decrease spasm severity, promote functional independence, improve motor recovery and decrease medication required for spasticity, which may help reduce the side effects that are possible with oral drug treatments. A 2004 study compared the effects of hydrotherapy on spasticity, oral baclofen dosage and Functional Independence Measure (FIM) scores of patients with a spinal cord injury (SCI). It was found that subjects who received hydrotherapy treatment obtained increased FIM scores and a decreased intake of oral baclofen medication. A 2009 study looked at the effect of hydrotherapy to decrease spasticity on post-stroke, hemiparetic patients with limited mobility and concluded that there was a significantly larger increase in FIM scores compared to the control group that did not receive hydrotherapy.

There is no cure for IBS but in the future gene therapy may offer a cure.

Treatments for IBS generally attempt to improve the appearance of the skin and the comfort of the sufferer. This is done by exfoliating and increasing the moisture of the skin. Common treatments include:

- Emollients: moisturisers, petroleum jelly or other emolients are used, often several times a day, to increase the moisture of the skin.

- Baths: long baths (possibly including salt) several times a week are used to soften the skin and allow exfoliation.

- Exfoliating creams: creams containing keratolytics such as urea, salicylic acid and lactic acid may be useful.

- Antiseptic washes: antiseptics may be used to kill bacteria in the skin and prevent odour.

- Retenoids: very severe cases may use oral retinoids to control symptoms but these have many serious side effects including, in the case of IBS, increased blistering.

Brain MRI shows vermis atrophy or hypoplasic. Cerebral and cerebellar atrophy with white matter changes in some cases.

Constant care is required to moisturise and protect the skin. The hard outer layer eventually peels off, leaving the vulnerable inner layers of the dermis exposed. Early complications result from infection due to fissuring of the hyperkeratotic plates and respiratory distress due to physical restriction of chest wall expansion.

Management includes supportive care and treatment of hyperkeratosis and skin barrier dysfunction. A humidified incubator is generally used. Intubation is often required until nares are patent. Nutritional support with tube feeds is essential until eclabium resolves and infants can begin nursing. Ophthalmology consultation is useful for the early management of ectropion, which is initially pronounced and resolves as scale is shed. Liberal application of petrolatum is needed multiple times a day. In addition, careful debridement of constrictive bands of hyperkeratosis should be performed to avoid digital ischemia. Cases of digital autoamputation or necrosis have been reported due to cutaneous constriction bands. Relaxation incisions have been used to prevent this morbid complication.

In the past, the disorder was nearly always fatal, whether due to dehydration, infection (sepsis), restricted breathing due to the plating, or other related causes. The most common cause of death was systemic infection and sufferers rarely survived for more than a few days. However, improved neonatal intensive care and early treatment with oral retinoids, such as the drug Isotretinoin (Isotrex), may improve survival. Early oral retinoid therapy has been shown to soften scales and encourage desquamation. After as little as two weeks of daily oral isotretinoin, fissures in the skin can heal, and plate-like scales can nearly resolve. Improvement in the eclabium and ectropion can also be seen in a matter of weeks. Children who survive the neonatal period usually evolve to a less severe phenotype, resembling a severe congenital ichthyosiform erythroderma. Patients continue to suffer from temperature dysregulation and may have heat and cold intolerance. Patients can also have generalized poor hair growth, scarring alopecia, contractures of digits, arthralgias, failure to thrive, hypothyroidism, and short stature. Some patients develop a rheumatoid factor-positive polyarthritis. Survivors can also develop fish-like scales and retention of a waxy, yellowish material in seborrheic areas, with ear adhered to the scalp.

The oldest known survivor is Nusrit "Nelly" Shaheen, who was born in 1984 and is in relatively good health as of April 2016. Lifespan limitations have not yet been determined with the new treatments.

A study published in 2011 in the Archives of Dermatology concluded, "Harlequin ichthyosis should be regarded as a severe chronic disease that is not invariably fatal. With improved neonatal care and probably the early introduction of oral retinoids, the number of survivors is increasing."

DOOR (deafness, onychdystrophy, osteodystrophy, and mental retardation) syndrome is a genetic disease which is inherited in an autosomal recessive fashion. DOOR syndrome is characterized by mental retardation, sensorineural deafness, abnormal nails and phalanges of the hands and feet, and variable seizures. A similar deafness-onychodystrophy syndrome is transmitted as an autosomal dominant trait and has no mental retardation. Some authors have proposed that it may be the same as Eronen Syndrome, but since both disorders are extremely rare it is hard to make a determination.

Although no specific treatment exists, the disease can be managed with anticonvulsants, physiotherapy, etc.

Pelizaeus–Merzbacher disease (PMD) is a rare central nervous system disorder in which coordination, motor abilities, and intellectual function are delayed to variable extents.

Marinesco–Sjögren syndrome (MSS), sometimes spelled Marinescu–Sjögren syndrome, is a rare autosomal recessive disorder.

Even though there is no way to cure the disease itself, there are ways to dampen the symptoms. These include medical help in form of pills, and using heavy lotions and oils.

To maintain the good health of the skin after the symptoms have dampened the person with the disease are advised to go on normally with their lives but to take precautions while showering. This is to take shorter, colder baths than usual to not stress the skin. It is also known to help to use bar-soap, instead of a liquid body wash.

Gillespie syndrome, also called aniridia, cerebellar ataxia and mental deficiency. is a rare genetic disorder. The disorder is characterized by partial aniridia (meaning that part of the iris is missing), ataxia (motor and coordination problems), and, in most cases, intellectual disability. It is heterogeneous, inherited in either an autosomal dominant or autosomal recessive manner. Gillespie syndrome was first described by American ophthalmologist Fredrick Gillespie in 1965.

Cohen syndrome (also known as Pepper syndrome or Cervenka syndrome, named after Michael Cohen, William Pepper and Jaroslav Cervenka, who researched the illness) is a genetic disorder.