Symptoms(and signs) that are consistent with this disorder are the following:

All types of Griscelli syndrome have distinctive skin and hair coloring.

Type 1 is associated with eurological abnormalities. These include delayed development, intellectual disability, seizures, hypotonia and eye abnormalities.

Type 2 - unlike type 1 - is not associated primary neurological disease but is associated with an uncontrolled T lymphocyte expansion and macrophage activation syndrome. It is often associated with the hemophagocytic syndrome. This latter condition may be fatal in the absence of bone marrow transplantation.

Persons with type 3 have the typical light skin and hair coloring but are otherwise normal.

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.

Juvenile hyaline fibromatosis (also known as "Fibromatosis hyalinica multiplex juvenilis," "Murray–Puretic–Drescher syndrome") is a very rare, autosomal recessive disease due to mutations in capillary morphogenesis protein-2 (CMG-2 gene). It occurs from early childhood to adulthood, and presents as slow-growing, pearly white or skin-colored dermal or subcutaneous papules or nodules on the face, scalp, and back, which may be confused clinically with neurofibromatosis.

Infants born with this condition have very short arms and legs, a narrow chest, and a prominent, rounded abdomen. This disorder is also characterized by an opening in the roof of the mouth (cleft palate), distinctive facial features, an inward- and downward-turning foot (clubfoot), and unusually positioned thumbs (hitchhiker thumbs).

The signs and symptoms of atelosteogenesis, type 2, are similar to those of another skeletal disorder called diastrophic dysplasia. Atelosteogenesis, type 2 tends to be more severe, however.

Griscelli syndrome type 2 (also known as "partial albinism with immunodeficiency") is a rare autosomal recessive syndrome characterized by variable pigmentary dilution, hair with silvery metallic sheen, frequent pyogenic infections, neutropenia, and thrombocytopenia.

The differential diagnosis is quite extensive and includes

- Buschke–Fischer–Brauer disease

- Curth–Macklin ichthyosis

- Gamborg Nielsen syndrome

- Greither disease

- Haber syndrome

- Hereditary punctate palmoplantar keratoderma

- Jadassohn–Lewandowsky syndrome

- Keratosis follicularis spinulosa decalvans

- Keratosis linearis with ichthyosis congenital and sclerosing keratoderma syndrome

- Meleda disease

- Mucosa hyperkeratosis syndrome

- Naegeli–Franceschetti–Jadassohn syndrome

- Naxos disease

- Olmsted syndrome

- Palmoplantar keratoderma and leukokeratosis anogenitalis

- Pandysautonomia

- Papillomatosis of Gougerot and Carteaud

- Papillon–Lefèvre syndrome

- Punctate porokeratotic keratoderma

- Richner–Hanhart syndrome

- Schöpf–Schulz–Passarge syndrome

- Unna Thost disease

- Vohwinkel syndrome

- Wong's dermatomyositis

The precise symptoms of a primary immunodeficiency depend on the type of defect. Generally, the symptoms and signs that lead to the diagnosis of an immunodeficiency include recurrent or persistent infections or developmental delay as a result of infection. Particular organ problems (e.g. diseases involving the skin, heart, facial development and skeletal system) may be present in certain conditions. Others predispose to autoimmune disease, where the immune system attacks the body's own tissues, or tumours (sometimes specific forms of cancer, such as lymphoma). The nature of the infections, as well as the additional features, may provide clues as to the exact nature of the immune defect.

Atelosteogenesis, type II is a severe disorder of cartilage and bone development. It is rare, and infants with the disorder are usually stillborn; however, those who survive birth die soon after

The signs/symptoms of this condition are consistent with the following:

- Intellectual disability,

- Muscular hypotonia

- Encephalitis

- Seizures

- Aphasia

2-hydroxyglutaric aciduria is an organic aciduria, and because of the stereoisomeric property of 2-hydroxyglutarate different variants of this disorder are distinguished:

Glutaric acidemia type 2 often appears in infancy as a sudden metabolic crisis, in which acidosis and low blood sugar (hypoglycemia) cause weakness, behavior changes, and vomiting. There may also be enlargement of the liver, heart failure, and a characteristic odor resembling that of sweaty feet. Some infants with glutaric acidemia type 2 have birth defects, including multiple fluid-filled growths in the kidneys (polycystic kidneys). Glutaric acidemia type 2 is a very rare disorder. Its precise incidence is unknown. It has been reported in several different ethnic groups.

Howel–Evans syndrome is an extremely rare condition involving thickening of the skin in the palms of the hands and the soles of the feet (hyperkeratosis). This familial disease is associated with a high lifetime risk of esophageal cancer. For this reason, it is sometimes known as tylosis with oesophageal cancer (TOC).

The condition is inherited in an autosomal dominant manner, and it has been linked to a mutation in the "RHBDF2" gene. It was first described in 1958.

Symptoms for Alström syndrome generally appear during infancy with great variability in age. Some of the symptoms include:

- Heart failure (Dilated cardiomyopathy) in over 60% of cases, usually within the first few weeks after birth, but sometimes the onset is in adolescence or adulthood.

- Light sensitivity and vision problems (Cone-rod dystrophy) in all cases, usually within 15 months of birth and progressively worsening until about 20 years of age

- Delays in early, developmental milestones in 50% of cases, learning disabilities in about 30% of cases

- Obesity in 100% of cases, apparent by 5 years of age, but often apparent in infancy (Alström infants usually have normal birth weights, and by adolescence, weights tend to be in the high-normal to normal range)

- Nystagmus (usually affects the children) one of the first symptoms to occur which causes involuntary rapid eye movement.

- Heart failure (Dilated cardiomyopathy) in over 60% of cases, usually within the first few weeks after birth, but sometimes the onset is in adolescence or adulthood.(chronic)

- Mild to moderate bilateral sensorineural hearing loss.

- Type 2 diabetes usually occurs in early childhood.

- Hyperinsulinemia/ insulin resistance—development of high level of insulin in blood.

- Steatosis (fatty liver) and elevated transaminases (liver enzymes) often develop in childhood and can progress in some patients to cirrhosis and liver failure.

- Endocrine dysfunctions may occur where the patient may experience an under or over active thyroid gland, weak growth hormone, increased androgen in females, and low testosterone in males.

- Slowly progressive kidney failure can occur in the second to fourth decade of life.

Almost all patients with this syndrome have some degree of mental retardation and facial dysmorphism (round face, deep-set eyes, thin upper lip). Behavioural problems are common. Brachymetaphalangism (metacarpal or metatarsal shortening) is reported in ~50% of cases overall, but is typically not evident below the age of 2 years. There is striking phenotypic variability, and the size and extent of the deleted region cannot be used as accurate predictors of prognosis. Some patients have additional problems such as congenital heart disease and seizures.

Some or all of the following may be seen in someone with Gorlin syndrome:

1. Multiple basal-cell carcinomas of the skin

2. Keratocystic odontogenic tumor: Seen in 75% of patients and is the most common finding. There are usually multiple lesions found in the mandible. They occur at a young age (19 yrs average).

3. Rib and vertebrae anomalies

4. Intracranial calcification

5. Skeletal abnormalities: bifid ribs, kyphoscoliosis, early calcification of falx cerebri (diagnosed with AP radiograph)

6. Distinct faces: frontal and temporoparietal bossing, hypertelorism, and mandibular prognathism

7. Bilateral ovarian fibromas

8. 10% develop cardiac fibromas

Primary immunodeficiencies are disorders in which part of the body's immune system is missing or does not function normally. To be considered a "primary" immunodeficiency, the cause of the immune deficiency must not be secondary in nature (i.e., caused by other disease, drug treatment, or environmental exposure to toxins). Most primary immunodeficiencies are genetic disorders; the majority are diagnosed in children under the age of one, although milder forms may not be recognized until adulthood. While there are over 100 recognized PIDs, most are very rare. About 1 in 500 people in the United States are born with a primary immunodeficiency. Immune deficiencies can result in persistent or recurring infections, autoinflammatory disorders, tumors, and disorders of various organs. There are currently no cures for these conditions; treatment is palliative and consists of managing infections and boosting the immune system.

2q37 monosomy is a rare genetic disorder caused by a deletion of a segment at the end of chromosome 2.

Infants with achondrogenesis, type 2 have short arms and legs, a small chest with short ribs, and underdeveloped lungs. Achondrogenesis, type 2 is a subtype of collagenopathy, types II and XI. This condition is also associated with a lack of bone formation (ossification) in the spine and pelvis. Typical facial features include a prominent forehead, a small chin, and, in some cases, an opening in the roof of the mouth (a cleft palate). The abdomen is enlarged, and affected infants often have a condition called hydrops fetalis in which excess fluid builds up in the body before birth. The skull bones may be soft, but they often appear normal on X-ray images. In contrast, bones in the spine (vertebrae) and pelvis do not harden.

Achondrogenesis, type 2 and hypochondrogenesis (a similar skeletal disorder) together affect 1 in 40,000 to 60,000 births. Achondrogenesis, type 2 is one of several skeletal disorders caused by mutations in the "COL2A1" gene. This gene provides instructions for making a protein that forms type II collagen. This type of collagen is found mostly in cartilage and in the clear gel that fills the eyeball (the vitreous). It is essential for the normal development of bones and other tissues that form the body's supportive framework (connective tissues). Mutations in the "COL2A1" gene interfere with the assembly of type II collagen molecules, which prevents bones and other connective tissues from developing properly.

Achondrogenesis, type 2 is considered an autosomal dominant disorder because one copy of the altered gene in each cell is sufficient to cause the condition. The disorder is not passed on to the next generation, however, because affected individuals hardly survive past puberty.

Glutaric acidemia type 2 is an autosomal recessive metabolic disorder that is characterised by defects in the ability of the body to use proteins and fats for energy. Incompletely processed proteins and fats can build up, leading to a dangerous chemical imbalance called acidosis.

Alström syndrome, also called Alstrom-Halgren syndrome, is a rare genetic disorder caused by mutations in the gene ALMS1. It is among the rarest genetic disorders in the world, as currently it has only 266 reported cases in medical literature and over 501 known cases in 47 countries. It was first described by Carl-Henry Alström in Sweden in 1959. Alstrom syndrome is sometimes confused with Bardet-Biedl syndrome, which has similar symptoms. Bardet-Biedl syndrome tends to have later onset in its symptoms. The likelihood of two carrier parents both passing the gene and therefore having a child affected by the syndrome is 25% with each pregnancy. The likelihood of having a child who is only a carrier of the gene is 50% with each pregnancy. The likelihood of a child receiving normal genes from both parents and being considered to be "genetically" normal is 25%. The risk for carrying the gene is equivalent for both males and females.

"Alström syndrome (AS) is a rare autosomal recessive disease characterized by multiorgan dysfunction. The key features are childhood obesity, blindness due to congenital retinal dystrophy, and sensorineural hearing loss. Associated endocrinologic features include hyperinsulinemia, early-onset type 2 diabetes, and hypertriglyceridemia."

Thus, AS shares several features with the common metabolic syndrome, namely obesity, hyperinsulinemia, and hypertriglyceridemia. Mutations in the ALMS1 gene have been found to be causative for AS with a total of 79 disease-causing mutations having been described." Prevalence estimates have ranged from 1 in 10,000 to fewer than 1 in 1,000,000 individuals in the general population.

Hepatoerythropoietic porphyria is a very rare form of hepatic porphyria caused by a disorder in both genes which code Uroporphyrinogen III decarboxylase (UROD).

It has a similar presentation to porphyria cutanea tarda (PCT), but with earlier onset. In classifications which define PCT type 1 as "sporadic" and PCT type 2 as "familial", hepatoerythropoietic porphyria is more similar to type 2.

Mutations in the human homologue of Drosophila patched(PTCH1), a tumor suppressor gene on chromosome 9, were identified as the underlying genetic event in this syndrome.

Complement 2 deficiency is a type of complement deficiency caused by any one of several different alterations in the structure of complement component 2.

It has been associated with an increase in infections.

It can present similarly to systemic lupus erythematosus (SLE).

SBCADD is included as a secondary target condition in most newborn screening programs, as the key analyte is the same as is used to identify isovaleric acidemia. Most cases have been Hmong individuals, who are asymptomatic. There are isolated case reports where individuals have been identified with SBCADD in addition to developmental delay and epilepsy. It is currently unclear what the complete clinical presentation of SBCADD looks like. There is some concern that these cases with additional symptoms may reflect an ascertainment bias rather than being a true representation of the clinical spectrum of the disease. Currently, there is no accepted treatment, as most affected individuals do not require any. Some recommend avoidance of valproic acid, as it can be a substrate for 2-methylbutyryl-CoA dehydrogenase.