Tricho-hepato-enteric syndrome is one particular form of intractable diarrhea of infancy, presenting typically in the first month of life. These babies were usually born small for their age and continue to experience failure to thrive, usually with a final short stature. Typical facial features include prominent forehead and cheeks, a broad nasal root and widely spaced eyes (hypertelorism). Their hairs are woolly, easily removed and poorly pigmented. Liver disease is mainly present as cirrhosis or fibrosis, and staining might reveal high iron content of the liver cells (consistent with hemochromatosis). Most evaluated patients had some degree of decrease in intelligence.

Tricho-hepato-enteric syndrome (THE), also known as syndromic or phenotypic diarrhea, is an extremely rare congenital bowel disorder which manifests itself as intractable diarrhea in infants with intrauterine growth retardation, hair and facial abnormalities. Many also have liver disease and abnormalities of the immune system. The associated malabsorption leads to malnutrition and failure to thrive.

It is thought to be a genetic disorder with an autosomal recessive inheritance pattern, although responsible genes have not been found and the exact cause remains unknown. Prognosis is poor; many patients die before the age of 5 (mainly from infections or cirrhosis), although most patients nowadays survive with intravenous feeding (parenteral nutrition).

Aneuploidy is often fatal, but in this case there is "X-inactivation" where the effect of the additional gene dosage due to the presence of extra X chromosomes is greatly reduced.

Much like Down syndrome, the mental effects of 49,XXXXY syndrome vary. Impaired speech and behavioral problems are typical. Those with 49,XXXXY syndrome tend to exhibit infantile secondary sex characteristics with sterility in adulthood and have some skeletal anomalies. Skeletal anomalies include:

- Genu valgum

- Pes cavus

- Fifth finger clinodactyly

The effects also include:

- Cleft palate

- Club feet

- Respiratory conditions

- Short or/and broad neck

- Low birth weight

- Hyperextensible joints

- Short stature

- Narrow shoulders

- Coarse features in older age

- Hypertelorism

- Epicanthal folds

- Prognathism

- Gynecomastia (rare)

- Muscular hypotonia

- Hypoplastic genitalia

- Cryptorchidism

- Congenital heart defects

- A very round face in infancy

Netherton syndrome is characterized by chronic skin inflammation, universal pruritus (itch), severe dehydration, and stunted growth. Patients with this disorder tend to have a hair shaft defect (trichorrhexis invaginata), also known as "bamboo hair". The disrupted skin barrier function in affected individuals also presents a high susceptibility to infection and allergy, leading to the development of scaly, reddish skin similar to atopic dermatitis. In severe cases, these atopic manifestations persist throughout the individual's life, and consequently post-natal mortality rates are high. In less severe cases, this develops into the milder ichthyosis linearis circumflexa.

Netherton syndrome has recently been characterised as a primary immunodeficiency, which straddles the innate and acquired immune system, much as does Wiskott-Aldrich syndrome. A group of Netherton patients have been demonstrated to have altered immunoglobulin levels (typically high IgE and low to normal IgG) and immature natural killer cells. These Natural Killer cells have a reduced lytic function; which can be improved with regular infusions of immunoglobulin (see 'Treatment'); although the mechanism for this is not clear.

Patients are more prone than healthy people to infections of all types, especially recurrent skin infections with staphylococcus. They may have more severe infections; but are not as vulnerable to opportunistic pathogens as patients with true Natural Killer cell deficiency-type SCID.

Netherton syndrome is a severe, autosomal recessive form of ichthyosis associated with mutations in the "SPINK5" gene. It is named after Earl W. Netherton (1910–1985), an American dermatologist who discovered it in 1958.

It is characterized by chronic, intractable diarrhea in new-born infants, starting in the first few days of life.

This results in metabolic acidosis and severe dehydration. Pregnancy and birth are usually normal.

Microvillus inclusion disease, also known as Davidson's disease, congenital microvillus atrophy and, less specifically, microvillus atrophy (note: microvillus is often misspelled as microvillous), is a rare genetic disorder of the small intestine that is inherited in an autosomal recessive pattern.

HIES often appears early in life with recurrent staphylococcal and candidal infections, pneumonias, and eczematoid skin.

- Autosomal dominant Hyper-IgE Syndrome caused by STAT3 defects, called Job Syndrome, have characteristic facial, dental, and skeletal abnormalities. Patients with STAT3 HIES may have either delay of or failure in shedding of primary teeth. The characteristic facial features are usually set by age 16. These include facial asymmetry, a prominent forehead, deep-set eyes, a broad nasal bridge, a wide, fleshy nasal tip, and mild prognathism. Additionally, facial skin is rough with prominent pores. Finally, some patients with STAT3 HIES have scoliosis, as well as bones that fracture easily.

- Autosomal recessive

49,XXXXY syndrome is an extremely rare aneuploidic sex chromosomal abnormality. It occurs in approximately 1 out of 85,000 to 100,000 males.

It is characterized by recurrent "cold" staphylococcal infections, unusual eczema-like skin rashes, severe lung infections that result in pneumatoceles (balloon-like lesions that may be filled with air or pus or scar tissue) and very high concentrations of the serum antibody IgE. Inheritance can be autosomal dominant or autosomal recessive. Many patients with autosomal dominant STAT3 hyper-IgE syndrome have characteristic facial and dental abnormalities, fail to lose their primary teeth, and have two sets of teeth simultaneously.

Theoretically, a mutation in any of the may cause disease, but below are some notable ones, with short description of symptoms:

- Adrenoleukodystrophy; leads to progressive brain damage, failure of the adrenal glands and eventually death.

- Alport syndrome; glomerulonephritis, endstage kidney disease, and hearing loss.

- Androgen insensitivity syndrome; variable degrees of undervirilization and/or infertility in XY persons of either gender

- Barth syndrome; metabolism distortion, delayed motor skills, stamina deficiency, hypotonia, chronic fatigue, delayed growth, cardiomyopathy, and compromised immune system.

- Blue cone monochromacy; low vision acuity, color blindness, photophobia, infantile nystagmus.

- Centronuclear myopathy; where cell nuclei are abnormally located in skeletal muscle cells. In CNM the nuclei are located at a position in the center of the cell, instead of their normal location at the periphery.

- Charcot–Marie–Tooth disease (CMTX2-3); disorder of nerves (neuropathy) that is characterized by loss of muscle tissue and touch sensation, predominantly in the feet and legs but also in the hands and arms in the advanced stages of disease.

- Coffin–Lowry syndrome; severe mental retardation sometimes associated with abnormalities of growth, cardiac abnormalities, kyphoscoliosis as well as auditory and visual abnormalities.

- Fabry disease; A lysosomal storage disease causing anhidrosis, fatigue, angiokeratomas, burning extremity pain and ocular involvement.

- Hunter's Syndrome; potentially causing hearing loss, thickening of the heart valves leading to a decline in cardiac function, obstructive airway disease, sleep apnea, and enlargement of the liver and spleen.

- Hypohidrotic ectodermal dysplasia, presenting with hypohidrosis, hypotrichosis, hypodontia

- Kabuki syndrome; multiple congenital anomalies and mental retardation.

- Spinal and bulbar muscular atrophy; muscle cramps and progressive weakness

- Lesch-Nyhan syndrome; neurologic dysfunction, cognitive and behavioral disturbances including self-mutilation, and uric acid overproduction (hyperuricemia)

- Lowe Syndrome; hydrophthalmia, cataracts, intellectual disabilities, aminoaciduria, reduced renal ammonia production and vitamin D-resistant rickets

- Menkes disease; sparse and coarse hair, growth failure, and deterioration of the nervous system

- Nasodigitoacoustic syndrome; mishaped nose, brachydactyly of the distal phalanges, sensorineural deafness

- Nonsyndromic deafness; hearing loss

- Norrie disease; cataracts, leukocoria along with other developmental issues in the eye

- Occipital horn syndrome; deformations in the skeleton

- Ocular albinism; lack of pigmentation in the eye

- Ornithine transcarbamylase deficiency; developmental delay and mental retardation. Progressive liver damage, skin lesions, and brittle hair may also be seen

- Siderius X-linked mental retardation syndrome; cleft lip and palate with mental retardation and facial dysmorphism, caused by mutations in the histone demethylase PHF8

- Simpson-Golabi-Behmel syndrome; coarse faces with protruding jaw and tongue, widened nasal bridge, and upturned nasal tip

- Spinal muscular atrophy caused by UBE1 gene mutation; weakness due to loss of the motor neurons of the spinal cord and brainstem

- Wiskott-Aldrich syndrome; eczema, thrombocytopenia, immune deficiency, and bloody diarrhea

- X-linked Severe Combined Immunodeficiency (SCID); infections, usually causing death in the first years of life

- X-linked sideroblastic anemia; skin paleness, fatigue, dizziness and enlarged spleen and liver.

Sabinas brittle hair syndrome, also called Sabinas syndrome or brittle hair-mental deficit syndrome, is an autosomal recessive congenital disorder affecting the integumentary system.

Symptoms include brittle hair, mild mental retardation and nail dysplasia. The syndrome was first observed in Sabinas, a small community in northern Mexico.

The principal biochemical features of the illness are reduced hair cystine levels, increased copper/zinc ratio, and presence of arginosuccinic acid in the blood and urine.

The key finding is brittle hair with low sulfur content, but alternating dark and light bands under polarizing microscopy, trichoschisis, and absent or defective cuticle are additional important clues for the diagnosis of trichothiodystrophy. Review of literature reveals extensive associated findings in trichothiodystrophy. Amino acid analyses of control hair when compared with those of patients with the Sabinas syndrome showed very striking differences with regard to content of sulphur amino acids. As in previous descriptions of amino acid abnormalities in the trichorrhexis nodosa of arginosuccinicaciduria, there were increases in lysine, aspartic acid, alanine, leucine, isoleucine, and tyrosine.

Trichothiodystrophy represents a central pathologic feature of a specific hair dysplasia associated with several disorders in organs derived from ectoderm and neuroectoderm. Trichothiodystrophy or TTD is a heterogeneous group of autosomal recessive disorders, characterized by abnormally sulfur deficient brittle hair and accompanied by ichthyosis and other manifestations.

Patients with trichothiodystrophy should have a thorough evaluation for other associated manifestations, including investigation of photosensitivity and DNA repair defects. Because the disease appears to be inherited in an autosomal recessive pattern, detection of low-sulfur brittle hair syndrome is also important for genetic counseling.

Individuals with acrodermatitis enteropathica may present with the following:

- Blistering of skin

- Dry skin

- Emotional lability

- Glossitis

- Pustule

Alopecia (loss of hair from the scalp, eyebrows, and eyelashes) may occur. Skin lesions may be secondarily infected by bacteria such as "Staphylococcus aureus" or fungi such as "Candida albicans". These skin lesions are accompanied by diarrhea.

The symptoms are very similar to graft-versus-host disease (GVHD). This is because the patients have some T cells with limited levels of recombination with the mutant RAG genes. These T cells are abnormal and have a very specific affinity for self antigens found in the thymus and in the periphery. Therefore, these T cells are auto-reactive and cause the GVHD phenotype.

A characteristic symptom is chronic inflammation of the skin, which appears as a red rash (early onset erythroderma). Other symptoms include eosinophilia, failure to thrive, swollen lymph nodes, swollen spleen, diarrhea, enlarged liver, low immunoglobulin levels (except immunoglobulin E, which is elevated), low T cell levels, and no B cells.

Omenn syndrome is an autosomal recessive severe combined immunodeficiency associated with hypomorphic missense mutations in immunologically relevant genes of T-cells (and B-cells) such as recombination activating genes (RAG1 and RAG2), IL-7 Receptor α gene (IL7Rα), DCLRE1C-Artemis, RMRP-CHH, DNA-Ligase IV, common gamma chain, WHN-FOXN1, ZAP-70 and complete DiGeorge anomaly (DiGeorge Syndrome; CHARGE).

Acrodermatitis enteropathica is an autosomal recessive metabolic disorder affecting the uptake of zinc through the inner lining of the bowel, the mucous membrane. It is characterized by inflammation of the skin (dermatitis) around bodily openings (periorificial) and the tips of fingers and toes (acral), hair loss (alopecia), and diarrhea. It can also be related to deficiency of zinc due to other, ie. congenital causes.

Other names for "acrodermatitis enteropathica" include Brandt syndrome and Danbolt–Closs syndrome.

The development of children born with INCL is normal for the first 8–18 months, but will then flounder and start to regress both physically and mentally. Motor skills and speech are lost, and optic atrophy causes blindness. A variety of neurological symptoms, such as epilepsy and myoclonic seizures, appear. The senses of hearing and touch remain unaffected. The average lifespan of an INCL child is 9–11 years.

Symptomatic presentation usually occurs between 6 and 24 months of age, but the majority of cases have been documented in children less than 1 year of age. The infantile form involves multiple organ systems and is primarily characterized by hypoketotic hypoglycemia (recurring attacks of abnormally low levels of fat breakdown products and blood sugar) that often results in loss of consciousness and seizure activity. Acute liver failure, liver enlargement, and cardiomyopathy are also associated with the infantile presentation of this disorder. Episodes are triggered by febrile illness, infection, or fasting. Some cases of sudden infant death syndrome are attributed to infantile CPT II deficiency at autopsy.

The specific and familial association of BIFE and PKC defines a novel clinical entity : the infantile convulsions and choreoathetosis syndrome. The first observation was made in four families where children were affected with nonfebrile convulsions at age 3–12 months.Partial epileptic seizures started with a psychomotor arrest and a deviation of the head and eyes to one side, followed inconstantly by unilateral jerks.In some cases, seizures generalized secondarily. None of the interictal electroencephalograms showed epileptiform abnormalities, and magnetic-resonance imaging were normal. These convulsions had a favorable outcome. At 5–8 years of age affected children developed abnormal movements. They presented with twisting movements of the hands of a reptilian type when stressed or embarrassed. They also developed jerky movements of the legs after running. Initially, abnormal movements were intermediate in speed between quick and slow, typical of paroxysmal choreoathetosis. Combinations of abnormal movements involving the arms, legs, trunk and occasionally the head were observed. The attacks lasted only a few minutes, occurring with a frequency of 5-30 episodes per day and were not accompanied by unconsciousness. In all patients, abnormal movements disappeared at 25–30 years of age without any treatment. Since the first report similar clinical presentations have been published which confirm the specificity of the ICCA syndrome.

An inherited disorder associated with the deposition of a steroid known as cholestanol in the brain and other tissues and with elevated levels of cholesterol in plasma but with normal total cholesterol level; it is characterized by progressive cerebellar ataxia beginning after puberty and by juvenile cataracts, juvenile or infantile onset chronic diarrhea, childhood neurological deficit, and tendineous or tuberous xanthomas.

Clostridial necrotizing enteritis (CNE), also called enteritis necroticans and pigbel, is an often fatal type of food poisoning caused by a β-toxin of "Clostridium perfringens", Type C. It occurs in some developing countries, but was also documented in Germany following World War II. The toxin is normally inactivated by certain proteolytic enzymes and by normal cooking, but when these protections are impeded, the disease emerges.

This exclusively myopathic form is the most prevalent and least severe phenotypic presentation of this disorder. Characteristic signs and symptoms include rhabdomyolysis (breakdown of muscle fibers and subsequent release of myoglobin), myoglobinuria, recurrent muscle pain, and weakness. It is important to note that muscle weakness and pain typically resolves within hours to days, and patients appear clinically normal in the intervening periods between attacks. Symptoms are most often exercise-induced, but fasting, a high-fat diet, exposure to cold temperature, or infection (especially febrile illness) can also provoke this metabolic myopathy. In a minority of cases, disease severity can be exacerbated by three life-threatening complications resulting from persistent rhabdomyolysis: acute kidney failure, respiratory insufficiency, and episodic abnormal heart rhythms. Severe forms may have continual pain from general life activity. The adult form has a variable age of onset. The first appearance of symptoms usually occurs between 6 and 20 years of age but has been documented in patients as young as 8 months as well as in adults over the age of 50. Roughly 80% cases reported to date have been male.

Cerebrotendineous xanthomatosis or cerebrotendinous xanthomatosis (CTX), also called cerebral cholesterosis, is an autosomal recessive form of xanthomatosis. It falls within a group of genetic disorders called the leukodystrophies.

CNE is a necrotizing inflammation of the small bowel (especially the jejunum but also the ileum). Clinical results may vary from mild diarrhea to a life-threatening sequence of severe abdominal pain, vomiting, bloody stool, ulceration of the small intestine with leakage (perforation) into the peritoneal cavity and possible death within a single day due to peritonitis. Many patients exhibit meteorism. Treatment involves suppressing the toxin-producing organisms with antibiotics such as penicillin G or metronidazole. About half of seriously ill patients require surgery for perforation, persistent intestinal obstruction, or failure to respond to the antibiotics. An investigational toxoid vaccine has been used successfully in some developing countries but is not available outside of research.