Autosomal recessive inheritance is the most likely, but sporadic mutations and autosomal dominant cases may also occur.

This syndrome has been associated with mutations in the ARID1B gene.

Mutations in SOX11 are associated to this syndrome.

The diagnosis is generally based on the presence of major and at least one minor clinical sign and can be confirmed by molecular genetic testing of the causative genes. Recent studies revealed that fifth finger nail/distal phalanx hypoplasia or aplasia is not a mandatory finding.

Coffin–Siris Syndrome is a rare genetic disorder that causes developmental delays and absent fifth finger and toe nails.

There had been 31 reported cases by 1991. The numbers of occurrence since then has grown and is reported to be around 80.

The differential includes Nicolaides–Baraitser syndrome.

The reported incidence of constriction ring syndrome varies from 1/1200 and 1/15000 live births. The prevalence is equally in male and female.

Fetomaternal factors like prematurity, maternal illnes, low birth weight and maternal drug exposure are predisposing factors for the constriction ring syndrome.

No positive relationship between CRS and genetic inheritance has been reported.

Tooth and nail syndrome (also known as "Hypodontia with nail dysgenesis," and "Witkop syndrome") is a rare disorder, first described in 1965, characterized by nails that are thin, small, and friable, and which may show koilonychia at birth.

It is associated with "MSX1".

Oral-facial-digital syndrome is a group of at least 13 related conditions that affect the development of the mouth, facial features, and digits in between 1 in 50,000 to 250,000 newborns with the majority of cases being type I (Papillon-League-Psaume syndrome).

People with yellow nail syndrome have been found to have a moderately reduced lifespan compared to people without the condition.

ANOTHER syndrome consists of alopecia, nail dystrophy, ophthalmic complications, thyroid dysfunction, hypohidrosis, ephelides and enteropathy, and respiratory tract infections. This is an autosomal recessive variant of ectodermal dysplasia.

Although it has been described in families, it has been suggested that it might not have a genetic link.

Sugarman syndrome is the common name of autosomal recessive oral-facial-digital syndrome type III, one of ten distinct genetic disorders that involve developmental defects to the mouth.

Alternative names for this condition include: Brachydactyly of the hands and feet with duplication of the first toes, Sugarman brachydactyly and Brachydactyly with major proximal phalangeal shortening.

Cenani–Lenz syndactylism is inherited in an autosomal recessive manner. This means the defective gene responsible for the disorder is located on an autosome, and two copies of the defective gene (one inherited from each parent) are required in order to be born with the disorder. The 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.

In a test of the theory that the locus associated with the disorder was at 15q13-q14, FMN1 and GREM1 were eliminated as candidates.

It is associated with "LRP4".

Ulnar–mammary syndrome or Schinzel syndrome is a cutaneous condition characterized by nipple and breast hypoplasia or aplasia.

It has been associated with TBX3.

Cenani–Lenz syndactylism, also known as Cenani–Lenz syndrome or Cenani–syndactylism, is an autosomal recessive congenital malformation syndrome involving both upper and lower extremities.

Limb–mammary syndrome is a cutaneous condition characterized by p63 mutations.

Nakajo syndrome, also called nodular erythema with digital changes, is a rare autosomal recessive congenital disorder first reported in 1939 by A. Nakajo in the offspring of consanguineous (blood relative) parents. The syndrome can be characterized by erythema (reddened skin), loss of body fat in the upper part of the body, and disproportionately large eyes, ears, nose, lips, and fingers.

Nakajo syndrome is inherited in an autosomal recessive manner. This means the defective gene responsible for the disorder is located on an autosome, and two copies of the defective gene (one inherited from each parent) are required in order to be born with the disorder. The 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.

The hallmark features of this syndrome are poorly developed fingernails, toenails, and patellae (kneecaps). Sometimes, this disease causes the affected person to have either no thumbnails or a small piece of a thumbnail on the edge of the thumb. The lack of development, or complete absence of fingernails results from the loss of function mutations in the LMX1B gene. This mutation may cause a reduction in dorsalising signals, which then results in the failure to normally develop dorsal specific structures such as nails and patellae. Other common abnormalities include elbow deformities, abnormally shaped pelvic (hip) bones, and kidney (renal) disease.

The Nail–patella syndrome is inherited via autosomal dominancy linked to aberrancy on human chromosome 9's q arm (the longer arm), 9q34. This autosomal dominancy means that only a single copy, instead of both, is sufficient for the disorder to be expressed in the offspring, meaning the chance of getting the disorder from an affected heterozygous parent is 50%. The frequency of the occurrence is 1/50,000. The disorder is linked to the ABO blood group locus.

It is associated with random mutations in the LMX1B gene. Studies have been conducted and 83 mutations of this gene have been identified.

Lelis syndrome it is a genetic disorder, a rare condition with dermatological and dental findings characterized by the association of ectodermal dysplasia (hypotrichosis and hypohidrosis) with acanthosis nigricans. Other clinical features may include palmoplantar hyperkeratosis, nail dystrophy, intellectual deficit, disturbances of skin pigmentation (perioral and periorbital hyperpigmentation, vitiligo, and perinevic leukoderma) and hypodontia. Transmission is autosomal recessive.

Muehrcke's nails, Muehrcke's lines, or leukonychia striata are changes in the fingernail that may be a sign of an underlying medical disorder or condition. Muehrcke's lines are white lines (leukonychia) that extend all the way across the nail and lie parallel to the lunula (half moon). In contrast to Beau's lines, they are not grooved. The lines are actually in the vascular nail bed underneath the nail plate, and as such, they do not move with nail growth. Meuhrcke's lines disappear when pressure is placed over the nail, blanching the underlying nail bed.

The appearance of Muehrcke's lines is nonspecific, but they are often associated with decreased protein synthesis, which may occur during periods of metabolic stress (e.g., after chemotherapy) and in hypoalbuminemic states such as the nephrotic syndrome.

Muehrcke's lines have also been described in infants with chronic hypolbuminemia secondary to various etiologies.

An example of Muehrcke's lines in the context of chemotherapy was published in the "New England Journal of Medicine" in 2007.

Muehrcke's lines were described by Robert C. Muehrcke (August 4, 1921 – September 7, 2003), an American physician in 1956.

There are three different theories to the cause of the constriction ring syndrome.

The first is the intrinsic theory, which was proposed by Streeter in 1930, implicates an anomaly in germ plasm resulting in the defects. This theory is reinforced by the clinical presentation of the constriction rings with other internal visceral and systematic anomalies. Because of these other anomalies the names “Constriction Ring Syndrome”, “Constriction Band Syndrome” and “Streeter Bands” are given to this defect/disease.

The second theory postulates the involvement of an intrauterine disruption during pregnancy followed by a cascade of events involving amniotic rupture. When spontaneous rupture of the amnion occurs early in the second trimester, the separation of amnion from chorion produces many small, thin strands that can become entangled within digits and toes.

The names “Amniotic Band Syndrome”, “Amniotic Disruption Complex", "Amniochorionic Mesoblastic Fibrous Strings", are based on this theory.

The third theory postulates the involvement of intrauterine trauma. Intrauterine trauma could be something like amniocentesis, or something like an fetal surgery. An intrauterine trauma could result in hemorrhage leading to acrosyndactyly. One study also showed the presence of bands as confirmed by sonography after fetal surgery.

Because of these different theories, there are many names for this syndrome. For a long time people believed the second theory about the amniotic rupture and strands. In the research cases not every child had a real (amniotic) strand. It could be that there has to be another explanation for the development of these anomalies.

Ectrodactyly–ectodermal dysplasia–cleft syndrome, or EEC, and also referred to as EEC syndrome (also known as "Split hand–split foot–ectodermal dysplasia–cleft syndrome") is a rare form of ectodermal dysplasia, an autosomal dominant disorder inherited as an genetic trait. EEC is characterized by the triad of ectrodactyly, ectodermal dysplasia, and facial clefts. Other features noted in association with EEC include vesicoureteral reflux, recurrent urinary tract infections, obstruction of the nasolacrimal duct, decreased pigmentation of the hair and skin, missing or abnormal teeth, enamel hypoplasia, absent punctae in the lower eyelids, photophobia, occasional cognitive impairment and kidney anomalies, and conductive hearing loss.

Raynaud's phenomenon, or "Secondary Raynaud's", occurs "secondary to" a wide variety of other conditions.

Secondary Raynaud's has a number of associations:

- Connective tissue disorders:

- scleroderma

- systemic lupus erythematosus

- rheumatoid arthritis

- Sjögren's syndrome

- dermatomyositis

- polymyositis

- mixed connective tissue disease

- cold agglutinin disease

- Ehlers-Danlos syndrome

- Eating disorders:

- anorexia nervosa

- Obstructive disorders:

- atherosclerosis

- Buerger's disease

- Takayasu's arteritis

- subclavian aneurysms

- thoracic outlet syndrome

- Drugs:

- beta-blockers

- cytotoxic drugs – particularly chemotherapeutics and most especially bleomycin

- ciclosporin

- bromocriptine

- ergotamine

- sulfasalazine

- anthrax vaccines whose primary ingredient is the Anthrax Protective Antigen

- stimulant medications, such as those used to treat ADHD (amphetamine and methylphenidate)

- OTC pseudoephedrine medications (Chlor-Trimeton, Sudafed, others)

- Occupation:

- jobs involving vibration, particularly drilling and prolonged use of a String trimmer (weed whacker), suffer from vibration white finger

- exposure to vinyl chloride, mercury

- exposure to the cold (e.g., by working as a frozen food packer)

- Others:

- physical trauma, such as that sustained in auto accidents or other traumatic events

- Lyme disease

- hypothyroidism

- cryoglobulinemia

- malignancy

- chronic fatigue syndrome

- reflex sympathetic dystrophy

- carpal tunnel syndrome

- magnesium deficiency

- multiple sclerosis

- erythromelalgia (clinically presenting as the opposite of Raynaud's, with hot and warm extremities) often co-exists in patients with Raynaud's)

Raynaud's can "herald" these diseases by periods of more than twenty years in some cases, making it effectively their first presenting symptom. This may be the case in the CREST syndrome, of which Raynaud's is a part.

Patients with Secondary Raynaud's can also have symptoms related to their underlying diseases. Raynaud's phenomenon is the initial symptom that presents for 70% of patients with scleroderma, a skin and joint disease.

When Raynaud's phenomenon is limited to one hand or one foot, it is referred to as Unilateral Raynaud's. This is an uncommon form, and it is always secondary to local or regional vascular disease. It commonly progresses within several years to affect other limbs as the vascular disease progresses.

Raynaud's disease, or "Primary Raynaud's", is diagnosed if the symptoms are "idiopathic", that is, if they occur by themselves and not in association with other diseases. Some refer to Primary Raynaud's disease as "being allergic to coldness". It often develops in young women in their teens and early adulthood. Primary Raynaud's is thought to be at least partly hereditary, although specific genes have not yet been identified.

Smoking increases frequency and intensity of attacks, and there is a hormonal component. Caffeine, estrogen, and non-selective beta-blockers are often listed as aggravating factors, but evidence that they should be avoided is not solid. People with the condition are more likely to have migraines and angina.

Odonto–tricho-ungual–digital–palmar syndrome is an autosomal dominant skin condition with salient clinical features of natal teeth, trichodystrophy, prominent interdigital folds, simian-like hands with transverse palmar creases, and ungual digital dystrophy.

Dysplastic nails are a cutaneous condition, and may be a subtle finding of ridging, flaking, or poor growth of the nails, or more diffuse with nearly complete loss of nails. This condition may be seen in a number of syndromes, including Dyskeratosis congenita and Nail–patella syndrome.