In the world less than 1 in 1.00.000 have HIDS [5]. 200 individuals throughout the world do suffer from MVK.

Mevalonate kinase deficiency, also called mevalonic aciduria and hyper immunoglobin D syndrome is an autosomal recessive metabolic disorder that disrupts the biosynthesis of cholesterol and isoprenoids.

It is characterized by an elevated level of immunoglobin D in the blood.

The enzyme is involved in biosynthesis of cholesterols and isoprenoids. The enzyme is necessary for the conversion of mevalonate to mevalonate-5-phosphate in the presence of Mg2+ [Harper’s biochemistry manual]. Mevalonate kinase deficiency causes the accumulation of mevalonate in urine and hence the activity of the enzyme is again reduced Mevalonate kinase deficiency. It was first described as HIDS in 1984.

Infant mortality is high for patients diagnosed with early onset; mortality can occur within less than 2 months, while children diagnosed with late-onset syndrome seem to have higher rates of survival. Patients suffering from a complete lesion of mut0 have not only the poorest outcome of those suffering from methylaonyl-CoA mutase deficiency, but also of all individuals suffering from any form of methylmalonic acidemia.

Delayed growth and development was noted in some patients, although not fully explained, this may be generally associated with the physiological difficulties implicit in errors of energy metabolism. In particular neurological impairment was conjecturally linked with the predominant role of aldolase A in the brain during development. However, this was not substantiated with direct enzymatic kinetic study.

Elevated liver glycogen in one patent was rationalised through an accumulation of fructose-1,6-bisphosphate leading to impaired glucose metabolism and increased diversion of hexose sugars from peripheral tissues. Within the liver the aldolase C isoform is unaffected and therefore hepatic metabolism is assumed to be normally functioning and compensatory processes may be operating.

Compromised immunity has also been indicated, relating to the predominance or exclusivity of aldolase A in leukocytes. This was correlated with recurrent infection in the Sicilian case.

Focal disruption of vital energy metabolism has thus far prevented complete investigation of non-catalytic perturbation. However relation to membrane structural stability has been implicated in the concurrence of aldolase A deficiency and dominant (mild) hereditary elliptocytosis, speculatively also relating to ATP depletion.

Aldolase A deficiency, also called ALDOA deficiency, red cell aldolase deficiency or glycogen storage disease type 12 (GSD XII) is an autosomal recessive metabolic disorder resulting in a deficiency of the enzyme aldolase A; the enzyme is found predominantly in red blood cells and muscle tissue. The deficiency may lead to hemolytic anaemia as well as myopathy associated with exercise intolerance and rhabdomyolysis in some cases.

Janus kinase 3 deficiency or JAK3 deficiency is a defect in the body's cytokine receptors and their signaling. JAK3 encodes Janus kinase 3, a tyrosine kinase that belongs to the Janus family. JAK3 functions in signal transduction and interacts with members of the STAT (signal transduction and activators of transcription) family. The cause of JAK3 deficiency. The deficiency causes the near absence of T lymphocytes and Natural killer cells; and normal or elevated B lymphocytes due to an autosomal recessive variant of severe combined immunodeficiency (SCID).

According to Clinicaltrials.gov, there are no current studies on hyperglycerolemia.

Clinicaltrials.gov is a service of the U.S. National Institutes of Health. Recent research shows patients with high concentrations of blood triglycerides have an increased risk of coronary heart disease. Normally, a blood glycerol test is not ordered. The research was about a child having elevated levels of triglycerides when in fact the child had glycerol kinase deficiency. This condition is known as pseudo-hypertriglyceridemia, a falsely elevated condition of triglycerides. Another group treated patients with elevated concentrations of blood triglycerides with little or no effect on reducing the triglycerides. A few laboratories can test for high concentrations of glycerol, and some laboratories can compare a glycerol-blanked triglycerides assay with the routine non-blanked method. Both cases show how the human body may exhibit features suggestive of a medical disorder when in fact it is another medical condition causing the issue.

Pyruvate kinase deficiency happens worldwide, however northern Europe, and Japan have many cases. The prevalence of pyruvate kinase deficiency is around 51 cases per million in the population (via gene frequency).

Glycerol Kinase Deficiency (GKD) is an X-linked recessive enzyme defect that is heterozygous in nature. Three clinically distinct forms of this deficiency have been proposed, namely infantile, juvenile, and adult. National Institutes of Health and its Office of Rare Diseases Research (ORDR) branch classifies GKD as a rare disease, known to affect fewer than 200,000 individuals in the United States. The responsible gene lies in a region containing genes in which deletions can cause Duchenne muscular dystrophy and adrenal hypoplasia congenita. Combinations of these three genetic defects including GKD are addressed medically as Complex GKD.

Glycerol Kinase Deficiency has two main causes associated with it.

- The first cause is isolated enzyme deficiency. The enzyme glycerol kinase is encoded by the X-chromosome in humans. It acts as a catalyst in the phosphorylation of glycerol to glycerol-3-phosphate which plays a key role in formation of triacylglycerol (TAG) and fat storage. There is no genotype–phenotype correlation in isolated GKD and it can be either symptomatic or asymptomatic. Symptomatic means that GKD shows symptoms when it persists in the body and asymptomatic means that the no symptoms appear in the body. In this deficiency the genotype is not associated with the phenotype. The presence of certain mutations in genes has no relation with the phenotype i.e. any resulting physical traits or abnormality.

- The second cause is a deletion or mutation of a single gene. GKD is described by mendelian inheritance and is an X-linked recessive trait due to which it occurs mainly in males and occasionally in females. GKD results when the glycerol kinase gene present on the locus Xp21 of the X chromosome is either deleted or mutated. Females have two X chromosomes and males have one X and one Y chromosome .The expression of recessive genes on the X chromosome is different in males and females. This is due to the fact that genes present on the Y chromosome do not pair up with genes on the X chromosome in males. In females the disorder is expressed only when there are two copies of the affected gene present on each X chromosome but since the glycerol kinase gene is present only on one X chromosome the disorder is not expressed in women. Women have a second good copy that can compensate for the defect on the first copy. On the other hand, males only need a single copy of the recessive gene for the disorder to be expressed. They do not have a second copy that can protect against any defect on the first copy.

Canine phosphofructokinase deficiency is found mostly in English Springer Spaniels and American Cocker Spaniels, but has also been reported in Whippets and Wachtelhunds. Mixed-breed dogs descended from any of these breeds are also at risk to inherit PFK deficiency.

In order to get Tarui’s disease, both parents must be carriers of the genetic defect so that the child is born with the full form of the recessive trait. The best indicator of risk is a family member with PFK deficiency.

Serology (detection on antibodies to a specific pathogen or antigen) is often used to diagnose viral diseases. Because XLA patients lack antibodies, these tests always give a negative result regardless of their real condition. This applies to standard HIV tests. Special blood tests (such as the western blot based test) are required for proper viral diagnosis in XLA patients.

It is not recommended and dangerous for XLA patients to receive live attenuated vaccines such as live polio, or the measles, mumps, rubella (MMR vaccine). Special emphasis is given to avoiding the oral live attenuated SABIN-type polio vaccine that has been reported to cause polio to XLA patients. Furthermore, it is not known if active vaccines in general have any beneficial effect on XLA patients as they lack normal ability to maintain immune memory.

XLA patients are specifically susceptible to viruses of the Enterovirus family, and mostly to: polio virus, coxsackie virus (hand, foot, and mouth disease) and Echoviruses. These may cause severe central nervous system conditions as chronic encephalitis, meningitis and death. An experimental anti-viral agent, pleconaril, is active against picornaviruses. XLA patients, however, are apparently immune to the Epstein-Barr virus (EBV), as they lack mature B cells (and so HLA co-receptors) needed for the viral infection. Patients with XLA are also more likely to have a history of septic arthritis.

It is not known if XLA patients are able to generate an allergic reaction, as they lack functional IgE antibodies.There is no special hazard for XLA patients in dealing with pets or outdoor activities. Unlike in other primary immunodeficiencies XLA patients are at no greater risk for developing autoimmune illnesses.

Agammaglobulinemia (XLA) is similar to the primary immunodeficiency disorder Hypogammaglobulinemia (CVID), and their clinical conditions and treatment are almost identical. However, while XLA is a congenital disorder, with known genetic causes, CVID may occur in adulthood and its causes are not yet understood.

XLA was also historically mistaken as Severe Combined Immunodeficiency (SCID), a much more severe immune deficiency ("Bubble boys").A strain of laboratory mouse, XID, is used to study XLA. These mice have a mutated version of the mouse Btk gene, and exhibit a similar, yet milder, immune deficiency as in XLA.

Renal failure is the major cause of morbidity and mortality in complete LCAT deficiency, while in partial deficiency (fish eye disease) major cause of morbidity is visual impairment due to corneal opacity. These patients have low HDL cholesterol but surprisingly premature atherosclerosis is not seen. However, there are some reported cases.

In adults, fibrates and statins have been prescribed to treat hyperglycerolemia by lowering blood glycerol levels. Fibrates are a class of drugs that are known as amphipathic carboxylic acids that are often used in combination with Statins. Fibrates work by lowering blood triglyceride concentrations. When combined with statins, the combination will lower LDL cholesterol, lower blood triglycerides and increase HDL cholesterol levels.

If hyperglycerolemia is found in a young child without any family history of this condition, then it may be difficult to know whether the young child has the symptomatic or benign form of the disorder. Common treatments include: a low-fat diet, IV glucose if necessary, monitor for insulin resistance and diabetes, evaluate for Duchenne muscular dystrophy, adrenal insufficiency & developmental delay.

The Genetic and Rare Diseases Information Center (GARD) does not list any treatments at this time.

It is not known how mevalonate kinase mutations cause the febrile episodes, although it is presumed that other products of the cholesterol biosynthesis pathyway, the prenylation chains (geranylgeraniol and farnesol) might play a role.

Genetic models of SLOS are created by knocking out the "DHCR7" gene. One study used homologous recombination to disrupt "DCHR7" in mouse embryonic stem cells. Similar to what is found in humans, heterozygous mice (having only one mutated allele) were phentoypically normal, and were crossed to produce pups (young mice) homozygous for the mutated allele. Although these pups died within the first day of life due to their inability to feed, they showed characteristics similar to humans with SLOS. They had decreased levels of cholesterol, increased levels of 7- and 8DHC, showed less growth and smaller birth weights, had craniofacial malformations, and less movement. Many also had a cleft palate, and decreased neuronal responses to glutamate. Overall however, the pups had fewer dysmorphic features than human patients with SLOS; they did not present limb, renal, adrenal or central nervous system malformations. This is explained by the fact that in rodents, maternal cholesterol can cross the placenta, and actually appears to be essential for the development of the fetus. In humans, very little maternal cholesterol is transferred to the fetus. In sum, the genetic mouse model is helpful to explain the neuropathophysiology of SLOS.

2,4 Dienoyl-CoA reductase deficiency is an inborn error of metabolism resulting in defective fatty acid oxidation caused by a deficiency of the enzyme 2,4 Dienoyl-CoA reductase. Lysine degradation is also affected in this disorder leading to hyperlysinemia. The disorder is inherited in an autosomal recessive manner, meaning an individual must inherit mutations in "NADK2," located at 5p13.2 from both of their parents. NADK2 encodes the mitochondrial NAD kinase. A defect in this enzyme leads to deficient mitochondrial nicotinamide adenine dinucleotide phosphate levels. 2,4 Dienoyl-CoA reductase, but also lysine degradation are performed by NADP-dependent oxidoreductases explaining how NADK2 deficiency can lead to multiple enzyme defects.

2,4-Dienoyl-CoA reductase deficiency was initially described in 1990 based on a single case of a black female who presented with persistent hypotonia. Laboratory investigations revealed elevated lysine, low levels of carnitine and an abnormal acylcarnitine profile in urine and blood. The abnormal acylcarnitine species was eventually identified as 2-trans,4-cis-decadienoylcarnitine, an intermediate of linoleic acid metabolism. The index case died of respiratory failure at four months of age. Postmortem enzyme analysis on liver and muscle samples revealed decreased 2,4-dienoyl-CoA reductase activity when compared to normal controls. A second case with failure to thrive, developmental delay, lactic acidosis and severe encephalopathy was reported in 2014.

2,4-Dienoyl-CoA reductase deficiency was included as a secondary condition in the American College of Medical Genetics Recommended Uniform Panel for newborn screening. Its status as a secondary condition means there was not enough evidence of benefit to include it as a primary target, but it may be detected during the screening process or as part of a differential diagnosis when detecting conditions included as primary target. Despite its inclusion in newborn screening programs in several states for a number of years, no cases have been identified via neonatal screening.

Several scientists have developed murine models of SSADH (Aldh5a1-/-) by typical gene methodology to create a uniform absence of the SSADH enzyme activity as well as accumulations of GHB and GABA in tissues and physiological fluids. The mice are born at the expected Mendelian frequencies for an autosomal recessive disorder. Most of the models include distinctive neurological phenotypes and exhibit hypotonia, truncal ataxia, generalized tonic-clonic seizures associated with 100% mortality. The mice uniformly die at 3-4 postnatal weeks. While this model is considered to be more severe than the phenotypes seen in humans, currently, it is the most highly regarded, valid, metabolic model to study potential therapeutic interventions for the disorder.

Studies have shown that alterations of both the GABA receptor and the GABA receptor early in the life of the Aldh5a1-/- mice can increase levels of GHB and enhance GABA release. Besides these effects, it has also been shown that "...a developmental down-regulation of GABA receptor mediated neurotransmission in Aldh5a1-/- mice likely contributes to the progression of generalized convulsive seizures seen in mutant animals." Other studies have confirmed the relationship between elevated levels of GHB and MAP kinase in mutant animals contribute to profound myelin abnormalities.

Teratogenic models are induced by feeding pregnant rats or mice inhibitors of DCHR7. Two common inhibitors are BM15766 (4-(2-[1-(4-chlorocinnamyl)piperazin-4-yl]ethyl)-benzoic acid) and AY9944 (truns-l,4-bis(2-chlorobenzylaminomethy1)cyclohexane dihydrochloride). These compounds have different chemical and physical properties, but induce similar effects. AY9944 has been shown to induce holoprosencephaly and sexual malformations similar to those seen in humans with SLOS. It is also known to cause impairments in the serotonin receptor, another defect commonly seen in SLOS patients. BM15766 has produced the lack of cholesterol and bile acid synthesis that is seen in SLOS patients with homozygous mutations. All teratogenic models can be effectively used to study SLOS; however, they present lower levels of 7-DHC and 8-DHC than are seen in humans. This can be explained by the fact that humans experience a permanent block in their DHCR7 activity, where mice and rats treated with inhibitors experience only transient blocks. Furthermore, different species of mice and rats are more resistant to teratogens, and may be less effective as models of SLOS. Teratogenic models are most commonly used to study more long-term effects of SLOS, because they survive longer than genetic models. For example, one study examined the retinal degeneration of SLOS, which in rats does not occur until at least one month after birth.

PASLI disease is a rare genetic disorder of the immune system. PASLI stands for “p110 delta activating mutation causing senescent T cells, lymphadenopathy, and immunodeficiency.” The immunodeficiency manifests as recurrent infections usually starting in childhood. These include bacterial infections of the respiratory system and chronic viremia due to Epstein-Barr virus (EBV) and/or cytomegalovirus (CMV). Individuals with PASLI disease also have an increased risk of EBV-associated lymphoma. Investigators Carrie Lucas, Michael Lenardo, and Gulbu Uzel at the National Institute of Allergy and Infectious Diseases at the U.S. National Institutes of Health and Sergey Nejentsev at the University of Cambridge, UK simultaneously described a mutation causing this condition which they called Activated PI3K Delta Syndrome (APDS).

Overall, the prognosis for patients with NOMID is not good, though many (80%) live into adulthood, and a few appear to do relatively well. They are at risk for leukemia, infections, and some develop deposits of protein aggregated called amyloid, which can lead to kidney failure and other problems. The neurologic problems are most troubling. The finding that other diseases are related and a better understanding of where the disease comes from may lead to more effective treatments.

Citrullinemia type I (CTLN1), also known as arginosuccinate synthetase deficiency, is a rare disease caused by a deficiency in argininosuccinate synthetase, an enzyme involved in excreting excess nitrogen from the body. There are mild and severe forms of the disease, which is one of the urea cycle disorders.

Glycogen storage disease type IX is a hereditary deficiency of glycogen phosphorylase kinase B that affects the liver and skeletal muscle tissue. It is inherited in an X-linked or autosomal recessive manner.

Equine SCID is an autosomal recessive disorder that affects the Arabian horse. Similar to the "bubble boy" condition in humans, an affected foal is born with no immune system, and thus generally dies of an opportunistic infection, usually within the first four to six months of life. There is a DNA test that can detect healthy horses who are carriers of the gene causing SCID, thus testing and careful, planned matings can now eliminate the possibility of an affected foal ever being born.

SCID is one of six genetic diseases known to affect horses of Arabian bloodlines, and the only one of the six for which there is a DNA test to determine if a given horse is a carrier of the allele. There are other genetic diseases that affect other horse breeds, and horses of part-Arabian bloodlines can be carriers of SCID.

Unlike SCID in humans, which can be treated, for horses, to date, the condition remains a fatal disease. When a horse is heterozygous for the gene, it is a carrier, but perfectly healthy and has no symptoms at all. If two carriers are bred together, however, classic Mendelian genetics indicate that there is a 50% chance of any given mating producing a foal that is a carrier heterozygous for the gene, and a 25% risk of producing a foal affected by the disease. If a horse is found to carry the gene, the breeder can choose to geld a male or spay a female horse so that they cannot reproduce, or they can choose to breed the known carrier only to horses that have been tested and found to be "clear" of the gene. In either case, careful breeding practices can avoid ever producing an SCID-affected foal.