Ornithine aminotransferase deficiency (also known as gyrate atrophy of the choroid and retina) is an inborn error of ornithine metabolism, caused by decreased activity of the enzyme ornithine aminotransferase. Biochemically, it can be detected by elevated levels of ornithine in the blood. Clinically, it presents initially with poor night vision, which slowly progresses to total blindness. It is believed to be inherited in an autosomal recessive manner. Approximately 200 known cases have been reported in the literature. The incidence is highest in Finland, estimated at 1:50,000.

Research suggests there can be some adverse effect on muscles and also the brain. The cause of this is somewhat unclear but may relate to very low levels of creatine often found in this population.

Tratement may include vitamin B6, Lysine or dramatic dietary change to minimise Arginine from patients diet. Research has indicated that these treatments may be somewhat effective in lowering ornathine blood concerntration levels in some patients, either in combination or individually. Vitamin B6 has been found to be very effective in a small proportion of patients.

Microvillus inclusion disease is thought to be extremely rare; only approximately 200 cases have been identified in children in Europe.

One patient, a teenage female living in Arizona, suddenly began to grow microvilli after thirteen years of TPN (Total Parenteral Nutrition) and Lipid dependency. She now enjoys a typical teenage diet and is seen regularly by her Gastroenterologist.

One patient from the UK was documented to achieve nutritional independence at age 3.

On 26 June 2009 a six-year-old girl diagnosed with microvillus inclusion disease became the third person in the UK to die of swine flu.

Quite often, the presenting symptom of ornithine aminotransferase (OAT) deficiency is myopia which progresses to night blindness. The onset of myopia is often in early childhood. Ophthalmological findings in affected individuals include constricted visual fields, posterior subcapsular cataracts (can begin in late teens), elevated dark adaptation thresholds and decreased or absent electroretinographic responses. Symptoms of OAT deficiency are progressive, and between the ages of 45 and 65, most affected individuals are almost completely blind.

In some cases, affected individuals will present in the neonatal period with disease that closely mimics a classic urea cycle defect, such as ornithine transcarbamylase deficiency, as the block in ornithine metabolism leads to secondary dysfunction of the urea cycle. These individuals present with hyperammonemia, poor feeding, failure to thrive and increased excretion of orotic acid.

There is no known direct treatment. Current treatment efforts focus on managing the complications of Wolfram syndrome, such as diabetes mellitus and diabetes insipidus.

It is nearly always fatal unless, like short bowel syndrome patients, treated with parenteral nutrition or an intestinal transplant. The patient is often classified as being in "intestinal failure" and treated with the cohort of patients known as "short bowel syndrome" patients.

Research for designing therapeutic trials is ongoing via the Washington University Wolfram Study Group, supported by The Ellie White Foundation for Rare Genetic Disorders and The Jack and J.T. Snow Scientific Research Foundation for Wolfram research.

Currently there is no effective therapy for dominant optic atrophy, and consequently, these patients are simply monitored for changes in vision by their eye-care professional. Children of patients should be screened regularly for visual changes related to dominant optic atrophy. Research is underway to further characterize the disease so that therapies may be developed.

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.

Iminoglycinuria, sometimes called familial iminoglycinuria, is an autosomal recessive disorder of renal tubular transport affecting reabsorption of the amino acid glycine, and the imino acids proline and hydroxyproline. This results in excess urinary excretion of all three acids ("-uria" denotes "in the urine").

Iminoglycinuria is a rare and complex disorder, associated with a number of genetic mutations that cause defects in both renal and intestinal transport systems of glycine and imino acids.

Imino acids typically contain an imine functional group, instead of the amino group found in amino acids. Proline is considered and usually referred to as an amino acid, but unlike others, it has a secondary amine. This feature, unique to proline, identifies proline also as an imino acid. Hydroxyproline is another imino acid, made from the naturally occurring hydroxylation of proline.

Congenital dSMA has a relatively stable disease course, with disability mainly attributed to increased contractures rather than loss of muscle strength. Individuals frequently use crutches, knee, ankle, and/or foot orthoses, or wheelchairs. Orthopaedic surgery can be an option for some patients with severely impaired movement. Physical therapy and occupational therapy can help prevent further contractures from occurring, though they do not reverse the effects of preexisting ones. Some literature suggests the use of electrical stimulation or botulinum toxin to halt the progression of contractures.

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.

Progressive retinal atrophy (PRA) is a group of genetic diseases seen in certain breeds of dogs and, more rarely, cats. Similar to retinitis pigmentosa in humans, it is characterized by the bilateral degeneration of the retina, causing progressive vision loss culminating in blindness. The condition in nearly all breeds is inherited as an autosomal recessive trait, with the exception of the Siberian Husky (inherited as an X chromosome linked trait) and the Bullmastiff (inherited as an autosomal dominant trait). There is no treatment.

Iminoglycinuria is believed to be inherited in an autosomal recessive manner. This means a defective gene responsible for the disorder is located on an autosome, and inheritance requires two copies of the defective gene—one from each parent. Parents of an individual with an autosomal recessive disorder both carry one copy of the defective gene, but usually do not experience any signs or symptoms of the disorder.

A non-inherited cause of excess urinary excretion of proline and glycine, similar to that found in iminoglycinuria, is quite common to newborn infants younger than 6 months. Sometimes referred to as neonatal iminoglycinuria, it is due to underdevelopment of high-affinity transport mechanisms within the renal circuit, specifically PAT2, SIT1 and SLC6A18. The condition corrects itself with age. In cases where this persists beyond childhood, however, inherited hyperglycinuria or iminoglycinuria may be suspected.

Cell based therapies using bone marrow stem cells as well as retinal pigment epithelial transplantation are being studied. A number of trials have occurred in humans with encouraging results.

There is no known cure to DSMA1, and care is primarily supportive. Patients require respiratory support which may include non-invasive ventilation or tracheal intubation. The child may also undergo additional immunisations and offered antibiotics to prevent respiratory infections. Maintaining a healthy weight is also important. Patients are at risk of undernutrition and weight loss because of the increased energy spent for breathing. Physical and occupational therapy for the child can be very effective in maintaining muscle strength.

There is no published practice standard for the care in DSMA1, even though the Spinal Muscular Atrophy Standard of Care Committee has been trying to come to a consensus on the care standards for DSMA1 patients. The discrepancies in the practitioners’ knowledge, family resources, and differences in patient’s culture and/or residency have played a part in the outcome of the patient.

A practical application of AMD-associated genetic markers is in the prediction of progression of AMD from early stages of the disease to neovascularization.

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.

Commonly affected breeds:

- Akita - Symptoms at one to three years old and blindness at three to five years old. Selective breeding has greatly reduced the incidence of this disease in this breed.

- Miniature longhaired Dachshund - Symptoms at six months old.

- Papillon - Slowly progressive with blindness at seven to eight years old.

- Tibetan Spaniel - Symptoms at three to five years old.

- Tibetan Terrier - PRA3/RCD4 disease of middle age dogs. http://www.ttca-online.org/html/Petersen-Jones_PRA_article.pdf

- Samoyed - Symptoms by three to five years old.

The disease has only been identified as distinct from SMA recently, so research is still experimental, taking place mostly in animal models. Several therapy pathways have been devised which include gene therapy, whereby an "IGHMBP2" transgene is delivered to the cell using a viral vector; small-molecule drugs like growth factors (e.g., IGF-1 and VEGF) or olesoxime; and transplantation of healthy motor neurons grown "in vitro" from the patient's stem cells. Studies in amyotrophic lateral sclerosis are also considered helpful because the condition is relatively similar to SMARD1.

A 2006 study followed 223 patients for a number of years. Of these, 15 died, with a median age of 65 years. The authors tentatively concluded that this is in line with a previously reported estimate of a shortened life expectancy of 10-15 years (12 in their data).

Geographic Atrophy (GA), also known as atrophic age-related macular degeneration (AMD) or advanced dry AMD, is an advanced form of age-related macular degeneration that can result in the progressive and irreversible loss of retina (photoreceptors, retinal pigment epithelium, choriocappillaris) which can lead to a loss of visual function over time. It is estimated that GA affects >5 million people worldwide and approximately 1 million patients in the US, which is similar to the prevalence of neovascular (wet) AMD, the other advanced form of the disease.

The incidence of advanced AMD, both geographic atrophy and neovascular AMD, increases exponentially with age and while there are therapies for wet AMD, GA currently has no approved treatment options. The aim of most current clinical trials is to reduce the progression of GA lesion enlargement.

Spinal muscular atrophy with lower extremity predominance (SMA-LED) is an extremely rare neuromuscular disorder of infants characterised by severe progressive muscle atrophy which is especially prominent in legs.

The disorder is associated with a genetic mutation in the "DYNC1H1" gene (the gene responsible also for one of the axonal types of Charcot–Marie–Tooth disease) and is inherited in an autosomal dominant manner. As with many genetic disorders, there is no known cure to SMA-LED.

The condition was first described in a multi-generational family by Walter Timme in 1917. Its linkage to the "DYNC1H1" gene was discovered in 2010 by M. B. Harms, et al., who also proposed the current name of the disorder.

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.

The pathogenesis of GA is multifactorial and is generally thought to be triggered by intrinsic and extrinsic stressors of the poorly regenerative retinal pigment epithelium (RPE), particularly oxidative stress caused by the high metabolic demand of photoreceptors, photo-oxidation, and environmental stressors such as cigarette smoke. Variations in several genes, particularly in the complement system, increase the risk of developing GA. This is an active area of research but the current hypothesis is that with aging, damage caused by these stressors accumulates, which coupled with a genetic predisposition, results in the appearance of drusen and lipofuscin deposits (early and intermediate AMD). These and other products of oxidative stress can trigger inflammation via multiple pathways, particularly the complement cascade, ultimately leading to loss of photoreceptors, RPE, and choriocapillaris, culminating in atrophic lesions that grow over time.

GAPO syndrome is a rare, autosomal recessive disorder that causes severe growth retardation, and has been observed fewer than 30 times before 2011. GAPO is an acronym that encompasses the predominant traits of the disorder: growth retardation, alopecia, pseudoanodontia (teeth failing to emerge from the gums), and worsening optic atrophy in some subjects. Other common symptoms include premature aging, large, prominent foreheads, and delayed bone aging. GAPO syndrome typically results in premature death around age 30-40, due to interstitial fibrosis and atherosclerosis.