"Best disease" is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition.

The inheritance pattern of adult-onset vitelliform macular dystrophy is definitively autosomal dominant. Many affected people, however, have no history of the disorder in their family and only a small number of affected families have been reported. This is because the penetrance of the condition is incomplete; therefore, it is possible for an individual to have a copy of the mutant allele and not display the VMD phenotype. The ratio of males to females is approximately 1:1.

Vitelliform macular dystrophy or vitelliform dystrophy is an irregular autosomal dominant eye disorder which can cause progressive vision loss. This disorder affects the retina, specifically cells in a small area near the center of the retina called the macula. The macula is responsible for sharp central vision, which is needed for detailed tasks such as reading, driving, and recognizing faces. The condition is characterized by yellow (or orange), slightly elevated, round structures similar to the yolk (Latin "vitellus") of an egg.

Approximately 1-2% of patients with defined SLE develop an optic neuropathy during the course of their disease. SLE-associated optic neuritis is rarely the presenting sign of the disease. The molecular pathogenesis is hypothesized, based on clinical features and the emerging understanding of mechanisms in SLE. Inflammation resulting from auto-antibodies, immune complexes, T-cells and complement, probably damages the components of the optic nerve, as well as the blood vessels (vasculitis). The resulting vasculitis causes a loss of blood supply to the nerve (ischemia). This combination of inflammation and ischemia may produce reversible changes such as demyelination alone, or more permanent damage axonal (necrosis), or a combination. The poor recovery of vision in AON despite anti-inflammatory treatment suggests that ischemia from the underlying vasculitis is an important component, but the details have not been established. It may be reasonable to consider that AON pathogenesis represents an incomplete expression of the SLE-associated optic neuropathy disease process.

AON is a rare disease and the natural history of the disease process is not well defined. Unlike typical optic neuritis, there is no association with multiple sclerosis, but the visual prognosis for AON is worse than typical optic neuritis. Thus AON patients have different treatment, and often receive chronic immunosuppression. No formal recommendation can be made regarding the best therapeutic approach. However, the available evidence to date supports treatment with corticosteroids and other immunosuppressive agents.

Early diagnosis and prompt treatment with systemic corticosteroids may restore some visual function but the patient may remain steroid dependent; vision often worsens when corticosteroids are tapered. As such, long-term steroid-sparing immunosuppressive agents may be required to limit the side-effects of steroids and minimize the risk of worsening vision.

Aspartylglucosaminuria is estimated to affect 1 in 18,500 people in Finland. This condition is less common in other countries, but the incidence is unknown. Even though this disease can occur in various races and ethnicities, another study backed this finding up by stating that 1 in 26,000 people in Finland had the disease and that 1 in 18,000 were carriers.

After trisomy 21 and fragile X syndrome, this is the most frequent multiple congenital anomaly/mental retardation syndrome in Finland.

Scleritis is not a common disease, although the exact prevalence and incidence are unknown. It is somewhat more common in women, and is most common in the fourth to sixth decades of life.

Individuals with AGU typically have normal development in infancy. Around the age of 2–4 years, they begin showing signs of developmental delay, but development is still progressing. Initial symptoms may present as clumsiness and/or speech delay. Individuals with AGU also show increased upper respiratory infections. Development continues until about puberty; however, an individual at 13–16 years of age typically shows mental and motor development similar to a 5-6 year old. Around puberty, a gradual decline in mental abilities and motor skills occurs. This progressive decline continues until about age 25–28, when rapid impairment of abilities occurs, resulting in severe mental retardation.

Most of the time, scleritis is not caused by an infectious agent. Histopathological changes are that of a chronic granulomatous disorder, characterized by fibrinoid necrosis, infiltration by polymorphonuclear cells, lymphocytes, plasma cells and macrophages. The granuloma is surrounded by multinucleated epitheloid giant cells and new vessels, some of which may show evidence of vasculitis.

Relationships between the disease and perlecan deficiency have been studied.

Morbidity and mortality range from both extremes as the significance correlate with the underlying systemic disease.

The causes of Kyrle disease are unclear and can be idiopathic. The only correlation that has shown light is the frequent association with an underlying disorder, such as, diabetes mellitus, chronic renal failure, hyperlipoproteinemia, hepatic abnormalities, and congestive heart failure. However, there had been cases where Kyrle disease was seen without any conjunction with the previous mentioned disorders. Due to the causes of Kyrle disease is unknown, the best way to prevent the disease is to prevent the disorders that are usually reported in conjunction with it.

By age 3 about 30% of rats have had cancer, whereas by age 85 about 30% of humans have had cancer. Humans, dogs and rabbits get Alzheimer's disease, but rodents do not. Elderly rodents typically die of cancer or kidney disease, but not of cardiovascular disease. In humans, the relative incidence of cancer increases exponentially with age for most cancers, but levels off or may even decline by age 60–75 (although colon/rectal cancer continues to increase).

People with the so-called segmental progerias are vulnerable to different sets of diseases. Those with Werner's syndrome suffer from osteoporosis, cataracts and cardiovascular disease, but not neurodegeneration or Alzheimer's disease; those with Down syndrome suffer type 2 diabetes and Alzheimer's disease, but not high blood pressure, osteoporosis or cataracts. In Bloom syndrome, those afflicted most often die of cancer.

Schwartz–Jampel syndrome (SJS) is a rare genetic disease caused by a mutation in the HSPG2 gene, which makes the protein perlecan, and causing osteochondrodysplasia associated with myotonia.

Most people with Schwartz–Jampel syndrome have a nearly normal life expectancy.

The intrahepatic shunts found in large dog breeds are passed on in a simple autosomal recessive way, while the extrahepatic shunts of the small breeds are inherited on a polygenic basis.

The exact cause of IOI is unknown, but infectious and immune-mediated mechanisms have been proposed. Several studies have described cases where onset of orbital pseudotumor was seen simultaneously or several weeks after upper respiratory infections. Another study by Wirostko et al. proposes that organisms resembling Mollicutes cause orbital inflammation by destroying the cytoplasmic organelles of parasitized cells.

Orbital pseudotumor has also been observed in association with Crohn’s disease, systemic lupus erythematosus, rheumatoid arthritis, diabetes mellitus, myasthenia gravis, and ankylosing spondylitis all of which strengthen the basis of IOI being an immune-mediated disease. Response to corticosteroid treatment and immunosuppressive agents also support this idea.

Trauma has also been seen to precede some cases of orbital pseudotumor. However, one study by Mottow-Lippe, Jakobiec, and Smith suggests that the release of circulating antigens caused by local vascular permeability triggers an inflammatory cascade in the affected tissues.

Although these mechanisms have been postulated as possible causes of IOI, their exact nature and relationships to the condition still remain unclear.

IOI or orbital pseudotumor is the second most common cause of exophthalmos following Grave’s orbitopathy and the third most common orbital disorder following thyroid orbitopathy and lymphoproliferative disease accounting for 5–17.6% of orbital disorders, There is no age, sex, or race predilection, but it is most frequently seen in middle-aged individuals. Pediatric cases account for about 17% of all cases of IOI.

Aging (senescence) increases vulnerability to age-associated diseases, whereas genetics determines vulnerability or resistance between species and individuals within species. Some age-related changes (like graying hair) are said to be unrelated to an increase in mortality. But some biogerontologists believe that the same underlying changes that cause graying hair also increase mortality in other organ systems and that understanding the incidence of age-associated disease will advance knowledge of the biology of senescence just as knowledge of childhood diseases advanced knowledge of human development.

Strategies for Engineered Negligible Senescence (SENS) is a research strategy which aims to repair a few "root causes" for age-related illness and degeneration, as well as develop medical procedures to periodically repair all such damage in the human body, thereby maintaining a youth-like state indefinitely. So far, the SENS programme has identified seven types of aging-related damage, and feasible solutions have been outlined for each. However, critics argue that the SENS agenda is optimistic at best, and that the aging process is too complex and little-understood for SENS to be scientific or implementable in the foreseeable future.

All clinical sub-types of hypophosphatasia have been traced to genetic mutations in the gene encoding TNSALP, which is localized on chromosome 1p36.1-34 in humans (ALPL; OMIM#171760). Approximately 204 distinct mutations have been described in the TNSALP gene. An up-to-date list of mutations is available online at The Tissue Nonspecific Alkaline Phosphatase Gene Mutations Database. About 80% of the mutations are missense mutations. The number and diversity of mutations results in highly variable phenotypic expression, and there appears to be a correlation between genotype and phenotype in hypophosphatasia”. Mutation analysis is possible and available in 3 laboratories.

Perinatal and infantile hypophosphatasia are inherited as autosomal recessive traits with homozygosity or compound heterozygosity for two defective TNSALP alleles. The mode of inheritance for childhood, adult, and odonto forms of hypophosphatasia can be either autosomal dominant or recessive. Autosomal transmission accounts for the fact that the disease affects males and females with equal frequency. Genetic counseling is complicated by the disease’s variable inheritance pattern, and by incomplete penetration of the trait.

Hypophosphatasia is a rare disease that has been reported worldwide and appears to affect individuals of all ethnicities. The prevalence of severe hypophosphatasia is estimated to be 1:100,000 in a population of largely Anglo-Saxon origin. The frequency of mild hypophosphatasia is more challenging to assess because the symptoms may escape notice or be misdiagnosed. The highest incidence of hypophosphatasia has been reported in the Mennonite population in Manitoba, Canada where one in every 25 individuals are considered carriers and one in every 2,500 newborns exhibits severe disease. Hypophosphatasia is considered particularly rare in people of African ancestry in the U.S.

Functional neurological symptom disorder can mimic many other conditions. Some alternative diagnoses for FND include:

- Hemiplegic migraine

- Multiple sclerosis

- Motor neurone disease

- Parkinson's

- Autoimmune disorders

- Ehlers–Danlos syndrome

- Stroke

- Vitamin B12 deficiency or pernicious anaemia

- Myasthenia gravis

Spinal osteoarthropathy is genetic, carried by parents and passed onto their offspring. Another known cause of this disease is a vitamin B12 deficiency in the reptile, which can be treated by injecting its food with a vitamin supplement.

The treatment options for hypohidrosis and anhidrosis is limited. Those with hypohidrosis should avoid drugs that can aggravate the condition (see medication-causes). They should limit activities that raise the core body temperature and if exercises are to be performed, they should be supervised and be performed in a cool, sheltered and well-ventilated environment. In instances where the cause is known, treatment should be directed at the primary pathology. In autoimmune diseases, such as Sjogren syndrome and systemic sclerosis, treatment of the underlying disease using immunosuppressive drugs may lead to improvement in hypohidrosis. In neurological diseases, the primary pathology is often irreversible. In these instances, prevention of further neurological damage, such as good glycaemic control in diabetes, is the cornerstone of management. In acquired generalized anhidrosis, spontaneous remission may be observed in some cases. Numerous cases have been reported to respond effectively to systemic corticosteroids. Although an optimum dose and regime has not been established, pulse methylprednisolone (up to 1000 mg ⁄ day) has been reported to have good effect.

It has been mapped to chromosome 2q31-36.

It has been associated with PNKD.

A reptile with spinal osteoarthropathy does not require a large vivarium. Like all vivaria it needs to be heated according to the particular reptile's needs, with a dark hiding area (e.g. a log or dark box), normal substrate and clean water for the reptile to access. It is advisable not to have anything too high for them to climb because the reptile's ability to hold onto branches (for example) is restricted; floor space is more important. It is best not to keep them with a tank-mate (especially a healthy one), since bullying may occur.

Hypohidrosis is diminished sweating in response to appropriate stimuli. While hyperhidrosis is a socially troubling but benign condition, hypohidrosis can lead to hyperthermia, heat exhaustion, heat stroke and potentially death. An extreme case of hypohydrosis in which there is a complete absence of sweating and the skin is dry is termed anhidrosis.