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.

Distal spinal muscular atrophy type 2 (DSMA2), also known as Jerash type distal hereditary motor neuropathy (HMN-J) — is a very rare childhood-onset genetic disorder characterised by progressive muscle wasting affecting lower and subsequently upper limbs. The disorder has been described in Arab inhabitants of Jerash region in Jordan as well as in a Chinese family.

The condition is linked to a genetic mutation in the "SIGMAR1" gene on chromosome 19 (locus 19p13.3) and is likely inherited in an autosomal recessive manner.

There is currently no cure for the disease but treatments to help the symptoms are available.

Prognosis strongly depends on which subtype of disease it is. Some are deadly in infancy but most are late onset and mostly manageable.

Treatment remains largely supportive. The behavioral disturbances of MPS-III respond poorly to medication. If an early diagnosis is made, bone marrow replacement may be beneficial. Although the missing enzyme can be manufactured and given intravenously, it cannot penetrate the blood–brain barrier and therefore cannot treat the neurological manifestations of the disease.

Along with many other lysosomal storage diseases, MPS-III exists as a model of a monogenetic disease involving the central nervous system.

Several promising therapies are in development. Gene therapy in particular is under Phase I/II clinical trial in France since October 2011 under the leadership of Paris-based biotechnology company Lysogene. Other potential therapies include chemical modification of deficient enzymes to allow them to penetrate the blood–brain barrier, stabilisation of abnormal but active enzyme to prevent its degradation, and implantation of stem cells strongly expressing the missing enzyme. For any future treatment to be successful, it must be administered as early as possible. Currently MPS-III is mainly diagnosed clinically, by which stage it is probably too late for any treatment to be very effective. Neonatal screening programs would provide the earliest possible diagnosis.

The flavonoid genistein decreases the pathological accumulation of glycosaminoglycans in Sanfilippo syndrome. "In vitro", animal studies and clinical experiments suggest that the symptoms of the disease may be alleviated by an adequate dose of genistein. Despite its reported beneficial properties, genistein also has toxic side effects.

Several support and research groups have been established to speed the development of new treatments for Sanfilippo syndrome.

In terms of treatment for individuals with Nezelof syndrome, which was first characterized in 1964, includes the following(how effective bone marrow transplant is uncertain) :

- Antimicrobial therapy

- IV immunoglobulin

- Bone marrow transplantation

- Thymus transplantation

- Thymus factors

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

Treatment is limited. Drugs can alleviate the symptoms, such as sleep difficulties and epilepsy. Physiotherapy helps affected children retain the ability to remain upright for as long as possible, and prevents some of the pain.

Recent attempts to treat INCL with cystagon have been unsuccessful.

Spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME), sometimes called Jankovic–Rivera syndrome, is a very rare neurodegenerative disease whose symptoms include slowly progressive muscle wasting (atrophy), predominantly affecting distal muscles, combined with denervation and myoclonic seizures.

SMA-PME is associated with a missense mutation (c.125C→T) or deletion in exon 2 of the "ASAH1" gene and is inherited in an autosomal recessive manner. As with many genetic disorders, there is no known cure to SMA-PME.

The condition was first described in 1979 by American researchers Joseph Jankovic and Victor M. Rivera.

In most cases, between the age of 2 and 4 oculomotor signals are present. Between the age of 2 and 8, telangiectasias appears. Usually by the age of 10 the child needs a wheel chair. Individuals with autosomal recessive cerebellum ataxia usually survive till their 20s; in some cases individuals have survived till their 40s or 50s.

Behr syndrome is characterized by the association of early-onset optic atrophy with spinocerebellar degeneration resulting in ataxia, pyramidal signs, peripheral neuropathy and developmental delay.

Although it is an autosomal recessive disorder, heterozygotes may still manifest much attenuated symptoms. Autosomal dominant inheritance also being reported in a family. Recently a variant of OPA1 mutation with phenotypic presentation like Behr syndrome is also described. Some reported cases have been found to carry mutations in the OPA1, OPA3 or C12ORF65 genes which are known causes of pure optic atrophy or optic atrophy complicated by movement disorder.

There is currently no cure for GAPO syndrome, but some options are available to reduce the symptoms. Nearsightedness, which affects some sufferers of the disease, can be treated by corrective lenses. Unfortunately, optic atrophy as a result of degradation of the optic nerve (common with GAPO syndrome) cannot be corrected. Corticosteroids have been proposed as a treatment for optic nerve atrophy, but their effectiveness is disputed, and no steroid based treatments are currently available.

Jalili syndrome is a genetic disorder characterized by the combination of cone-rod dystrophy of the retina and amelogenesis imperfecta. It was characterized in 1988 by Dr. I. K. Jalili and Dr. N. J. D. Smith, following the examination of 29 members of an inbred, Arab family living within the Gaza Strip.

The severity of different forms of PCH varies, but many children inheriting the mutated gene responsible do not survive infancy or childhood; nevertheless, some individuals born with PCH have reached adulthood.

There is currently no specific treatment available for either of these so-called progeroid syndromes. With this in mind, what is most important when making a differential diagnosis with them is based on the prognosis, which appears to be far better in acrogeria.

Type II tyrosinemia is caused by a deficiency of the enzyme tyrosine aminotransferase (), encoded by the gene "TAT". Tyrosine aminotransferase is the first in a series of five enzymes that converts tyrosine to smaller molecules, which are excreted by the kidneys or used in reactions that produce energy. This form of the disorder can affect the eyes, skin, and mental development. Symptoms often begin in early childhood and include excessive tearing, abnormal sensitivity to light (photophobia), eye pain and redness, and painful skin lesions on the palms and soles. About half of individuals with type II tyrosinemia are also mentally challenged. Type II tyrosinemia occurs in fewer than 1 in 250,000 individuals.

Medical Care

- Treatment may be provided on an outpatient basis.

- Cataracts that do not regress or disappear with therapy may require hospitalization for surgical removal.

Surgical Care

- Cataracts may require surgical removal.

Consultations

- Biochemical geneticist

- Nutritionist

- Ophthalmologist

Diet

- Diet is the foundation of therapy. Elimination of lactose and galactose sources suffices for definitive therapy.

Activity

- No restriction is necessary.

(Roth MD, Karl S. 2009)

Autoimmune polyendocrine syndrome type 2, a form of autoimmune polyendocrine syndrome also known as Schmidt's syndrome, or APS-II, is the most common form of the polyglandular failure syndromes. It is heterogeneous and has not been linked to one gene. Rather, individuals are at a higher risk when they carry a particular human leukocyte antigen (HLA-DQ2, HLA-DQ8 and HLA-DR4). APS-II affects women to a greater degree than men.

The differential diagnosis for this condition consists of acquired immune deficiency syndrome and severe combined immunodeficiency syndrome

Acrogeria is extremely rare, with only about 40 cases having been reported in the medical literature, since 1941.

There is currently no treatment or cure for Waardenburg syndrome. The symptom most likely to be of practical importance is deafness, and this is treated as any other irreversible deafness would be. In marked cases there may be cosmetic issues. Other abnormalities (neurological, structural, Hirschsprung disease) associated with the syndrome are treated symptomatically.

Since Usher syndrome results from the loss of a gene, gene therapy that adds the proper protein back ("gene replacement") may alleviate it, provided the added protein becomes functional. Recent studies of mouse models have shown one form of the disease—that associated with a mutation in myosin VIIa—can be alleviated by replacing the mutant gene using a lentivirus. However, some of the mutated genes associated with Usher syndrome encode very large proteins—most notably, the "USH2A" and "GPR98" proteins, which have roughly 6000 amino-acid residues. Gene replacement therapy for such large proteins may be difficult.

Tyrosinemia type II (Oculocutaneous tyrosinemia, Richner-Hanhart syndrome) is an autosomal recessive condition with onset between ages 2 and 4 years, when painful circumscribed calluses develop on the pressure points of the palm of the hand and sole of the foot.

Bietti's crystalline dystrophy (BCD), also called Bietti crystalline corneoretinal dystrophy, is a rare autosomal recessive eye disease named after Dr. G. B. Bietti.

BCD is a rare disease and appears to be more common in people with Asian ancestry.

Lethal congenital contracture syndrome 1 (LCCS1), also called Multiple contracture syndrome, Finnish type, is an autosomal recessive genetic disorder characterized by total immobility of a fetus, detectable at around the 13th week of pregnancy. LCCS1 invariably leads to prenatal death before the 32nd gestational week. LCCS1 is one of 40 Finnish heritage diseases. It was first described in 1985 and since then, approximately 70 cases have been diagnosed.