The specific cause of camptodactyly remains unknown, but there are a few deficiencies that lead to the condition. A deficient lumbrical muscle controlling the flexion of the fingers, and abnormalities of the flexor and extensor tendons.

A number of congenital syndromes may also cause camptodactyly:

- Jacobsen syndrome

- Beals Syndrome

- Blau syndrome

- Freeman-Sheldon syndrome

- Cerebrohepatorenal syndrome

- Weaver syndrome

- Christian syndrome 1

- Gordon Syndrome

- Jacobs arthropathy-camptodactyly syndrome

- Lenz microphthalmia syndrome

- Marshall-Smith-Weaver syndrome

- Oculo-dento-digital syndrome

- Tel Hashomer camptodactyly syndrome

- Toriello-Carey syndrome

- Stuve-Wiedemann syndrome

- Loeys-Dietz syndrome

- Fryns syndrome

- Marfan's syndrome

- Carnio-carpo-tarsal dysthropy

Roberts syndrome is an extremely rare condition that only affects about 150 reported individuals. Although there have been only about 150 reported cases, the affected group is quite diverse and spread worldwide. Parental consanguinity (parents are closely related) is common with this genetic disorder. The frequency of Roberts syndrome carriers is unknown.

While not always pathological, it can present as a birth defect in multiple syndromes including:

- Catel–Manzke syndrome

- Bloom syndrome

- Coffin–Lowry syndrome

- congenital rubella

- Cri du chat syndrome

- DiGeorge's syndrome

- Ehlers-Danlos syndrome

- fetal alcohol syndrome

- Hallermann-Streiff syndrome

- Hemifacial microsomia (as part of Goldenhar syndrome)

- Juvenile idiopathic arthritis

- Marfan syndrome

- Noonan syndrome

- Pierre Robin syndrome

- Prader–Willi syndrome

- Progeria

- Russell-Silver syndrome

- Seckel syndrome

- Smith-Lemli-Opitz syndrome

- Treacher Collins syndrome

- Trisomy 13 (Patau syndrome)

- Trisomy 18 (Edwards syndrome)

- Wolf–Hirschhorn syndrome

- X0 syndrome (Turner syndrome)

The name is derived from the ancient Greek words "kamptos" ("bent") and "daktylos" ("finger").

Males are twice as likely as females to have this characteristic, and it tends to run in families. In its non-symptomatic form, it is more common among Asians and Native Americans than among other populations, and in some families there is a tendency to inherit the condition unilaterally, that is, on one hand only.

The presence of a single transverse palmar crease can be, but is not always, a symptom associated with abnormal medical conditions, such as fetal alcohol syndrome, or with genetic chromosomal abnormalities, including Down Syndrome (chromosome 21), cri du chat syndrome (chromosome 5), Klinefelter syndrome, Wolf-Hirschhorn Syndrome, Noonan syndrome (chromosome 12), Patau syndrome (chromosome 13), IDIC 15/Dup15q (chromosome 15), Edward's syndrome (chromosome 18), and Aarskog-Scott syndrome (X-linked recessive), or autosomal recessive disorder, such as Leaukocyte adhesion deficiency-2 (LAD2). A unilateral single palmar crease was also reported in a case of chromosome 9 mutation causing Nevoid basal cell carcinoma syndrome and Robinow syndrome. It is also sometimes found on the hand of the affected side of patients with Poland Syndrome, and craniosynostosis.

It is likely that this syndrome is inherited in an autosomal dominant fashion, however there may be a recessive form with hypotonia and developmental delay.

At this time, there are no other phenotypes (observable expressions of a gene) that have been discovered for mutations in the ESCO2 gene.

Muenke syndrome is caused by a specific gene mutation in the FGFR3 gene. The mutation arises randomly; there is no full understanding for what causes this mutation. This mutation causes the FGFR3 protein to be overly active; it interferes with normal bone growth, and allows skull bones to fuse prematurely. There is no connection between anything mother did (or did not do) to activate the syndrome. If neither of the parents have Muenke syndrome, chances of having another child with the syndrome are minimal.

This condition is inherited in an autosomal dominant pattern. This means if a parent has Muenke syndrome, every newborn has a 50% chance of inheriting the syndrome.

Low-set ears are ears with depressed positioning of the pinna two or more standard deviations below the population average.

It can be associated with conditions such as:

- Down's syndrome

- Turner Syndrome

- Noonan syndrome

- Patau syndrome

- DiGeorge syndrome

- Cri du chat syndrome

- Edwards syndrome

- Fragile X syndrome

It is usually bilateral, but can be unilateral in Goldenhar syndrome.

Acrocephalosyndactylia (or acrocephalosyndactyly) is the common presentation of craniosynostosis and syndactyly.

Respiratory complications are often cause of death in early infancy.

The original report was of a family in Cardiff, United Kingdom. There are subsequent reports of patients from the USA, France, Australia, UAE, India and from Cuba.

It can be detected by the naked eye as well as dental or skull X-Ray testing.

Both autosomal dominant and recessive forms of Larsen syndrome have been reported. The former is significantly more common than the latter. Symptoms such as syndactyly, cleft palate, short stature, and cardiac defects are seen more commonly in individuals with the autosomal recessive form of the disorder. A lethal form of the disorder has been reported it is described as being a combination of the Larsen phenotype and pulmonary hypoplasia.

The first gene that could cause the syndrome is described recently and is called NF1X (chromosome 19: 19p13.1).

Filamins are cytoplasmic proteins that regulate the structure and activity of the cytoskeleton. These proteins serve as scaffolds on which intracellular signaling and protein trafficking are organized. Filamin B has been found to be expressed in human growth plate chondrocytes, which are especially important in vertebrae segmentation and skeleton morphogenesis. Genetic analysis of patients with Larsen syndrome has found the syndrome is caused by missense mutations in the gene that codes for filamin B. These mutations cause an accelerated rate of apoptosis in the epiphyseal growth plates of individuals with the mutation. The defects can cause short stature and other symptoms associated with Larsen syndrome.

It has several different types:

- type 1 - Apert syndrome

- type 2 - Crouzon syndrome

- type 3 - Saethre-Chotzen syndrome

- type 5 - Pfeiffer syndrome

A related term, "acrocephalopolysyndactyly" (ACPS), refers to the inclusion of polydactyly to the presentation. It also has multiple types:

- type 1 - Noack syndrome; now classified with Pfeiffer syndrome

- type 2 - Carpenter syndrome

- type 3 - Sakati-Nyhan-Tisdale syndrome

- type 4 - Goodman syndrome; now classified with Carpenter syndrome

- type 5 - Pfeiffer syndrome

It has been suggested that the distinction between "acrocephalosyndactyly" versus "acrocephalopolysyndactyly" should be abandoned.

Muenke syndrome is inherited in an autosomal dominant pattern. In some cases, an affected person inherits the mutation from one affected parent. If a patient is shown to have Muenke, they have a 50/50 chance of passing it on to their children. Not all cases of Muenke however is obvious. Other cases may result from new mutations in the gene. These cases occur in people with no history of the disorder in their family.

A single mutation in the FGFR3 gene cause this syndrome. The FGFR3 gene provides instructions for making a protein that is involved in the development and maintenance of bone and brain tissue. This mutation causes the FGFR3 protein to be overly active, which interferes with normal bone growth and allows the bones of the skull to fuse before they should.

As stated by researchers at the University of Washington, Muenke syndrome is inherited in an autosomal dominant manner with incomplete penetrance and variable expressivity.” Prenatal diagnosis for pregnancies at increased risk is possible if the defining mutation has been identified in the family (Agochukwu et.al. 2006). According to the article "Craniosynostosis: Molecular Genetics," penetrance is higher in females (87%) than in males (76%). Muenke syndrome is estimated to account for 25%-30% of all genetic causes of craniosynostosis according to the Journal of Anatomy.

Some people may have some mental slowness, but children with this condition often have good social skills. Some males may have problems with fertility.

In humans, a single transverse palmar crease is a single crease that extends across the palm of the hand, formed by the fusion of the two palmar creases (known in palmistry as the "heart line" and the "head line") and is found in people with Down Syndrome. It is also found in 1.5% of the general population in at least one hand.

Because it resembles the usual condition of non-human simians, it is also known as a simian crease or simian line, although these terms have widely fallen out of favor due to their pejorative connotation.

Heart-hand syndrome type 2 is also known as Berk–Tabatznik syndrome. Berk–Tabatznik syndrome is a condition with an unknown cause that shows symptoms of short stature, congenital optic atrophy and brachytelephalangy. This condition is extremely rare with only two cases being found.

Hay–Wells syndrome is also known as AEC syndrome; this is short for "ankyloblepharon–ectodermal dysplasia–clefting syndrome", "ankyloblepharon filiforme adnatum–ectodermal dysplasia–cleft palate syndrome", "ankyloblepharon–ectodermal defects–cleft lip/palate (AEC) syndrome", "ankyloblepharon–ectodermal defect–cleft lip and/or palate syndrome", or "ankyloblepharon ectodermal dysplasia and clefting". Hay–Wells syndrome, or Ankyloblepharon-Ectodermal Dysplasia-Clefting (AEC) syndrome, is one of over one-hundred forms of ectodermal dysplasia; a collection of inherited diseases that cause atypical development of nails, glands, teeth, and hair. Males and females are equally affected by Hay–Wells syndrome. No demographic has been shown to be especially susceptible to the syndrome. In the United States, Hay-Wells like syndromes occur in only one in 100,000 births. Symptoms are apparent at birth, or become apparent when atypical development of teeth occurs. Major symptoms of Hay–Wells syndrome include: sparse hair and eyelashes, missing teeth, cleft palate, cleft lip with fusing of the upper and lower eyelids, and deformed nails. Therefore, a diagnosis of Hay–Wells syndrome is largely based upon the physical clinical presentation of the patient.

In a newborn boy thought to have Fryns syndrome, Clark and Fenner-Gonzales (1989) found mosaicism for a tandem duplication of 1q24-q31.2. They suggested that the gene for this disorder is located in that region. However, de Jong et al. (1989), Krassikoff and Sekhon (1990), and Dean et al. (1991) found possible Fryns syndrome associated with anomalies of chromosome 15, chromosome 6, chromosome 8(human)and chromosome 22, respectively. Thus, these cases may all represent mimics of the mendelian syndrome and have no significance as to the location of the gene for the recessive disorder.

By array CGH, Slavotinek et al. (2005) screened patients with DIH and additional phenotypic anomalies consistent with Fryns syndrome for cryptic chromosomal aberrations. They identified submicroscopic chromosome deletions in 3 probands who had previously been diagnosed with Fryns syndrome and had normal karyotyping with G-banded chromosome analysis. Two female infants were found to have microdeletions involving 15q26.2 (see 142340), and 1 male infant had a deletion in band 8p23.1 (see 222400).

The incidence of Fraser syndrome is 0.043 per 10,000 live born infants and 1.1 in 10,000 stillbirths, making it a rare syndrome.

Heart-hand syndrome type 3 is very rare and has been described only in three members of a Spanish family. It is also known as Heart-hand syndrome, Spanish type.