Liebenberg Syndrome is a rare autosomal genetic disease that involves a deletion mutation upstream of the PITX1 gene, which is one that's responsible for the body's organization, specifically in forming lower limbs. In animal studies, when this deletion was introduced to developing birds, their wing buds were noted to take on limb-like structures.

The condition was first described by Dr. F. Liebenberg in 1973 while he followed multiple generations of a South African family, but it has since been noticed in other family lineages across the world.

Cooks syndrome is a hereditary disorder which is characterized in the hands by bilateral nail hypoplasia on the thumb, index finger, and middle finger, absence of fingernails (anonychia) on the ring finger and little finger, lengthening of the thumbs, and bulbousness of the fingers. In the feet, it is characterized by absence of toenails and absence/hypoplasia of the distal phalanges. In the second study of this disorder, it was found that the intermediate phalanges, proximal phalanges, and metacarpals were unaffected.

The disorder was first described by Cooks "et al." in 1985 after being discovered in two generations of one family. It was proposed that the inheritance of the disorder is autosomal dominant. A second family, this with three affected generations, confirmed that the inheritance of the disorder is autosomal dominant. Although several genetic disorders exist which can cause anonychia and onychodystrophy, such disorders often cause other anomalies such as deafness, mental retardation, and defects of the hair, eyes, and teeth. Cooks syndrome is not known to cause any such anomalies.

In 1999, a pair of siblings was found with brachydactyly type B. Because the disorder primarily affected the nails and distal phalanges, the research group concluded that brachydactyly type B and Cooks syndrome are the same disorder. However, in 2007, a 2-year-old girl was found with symptoms consistent with both brachydactyly type B and Cooks syndrome. It was found that the two syndromes were distinct clinically, radiologically, and genetically.

Surgery is an option to correct some of the morphological changes made by Liebenberg Syndrome. Cases exist where surgery is performed to correct radial deviations and flexion deformities in the wrist. A surgery called a carpectomy has been performed on a patient whereby a surgeon removes the proximal row of the carpal bones. This procedure removes some of the carpal bones to create a more regular wrist function than is observed in people with this condition.

The disorder is thought to be related to mutations in the PDE3A gene.

Ellis–van Creveld Syndrome (also called "chondroectodermal dysplasia" or "mesoectodermal dysplasia" but see 'Nomenclature' section below) is a rare genetic disorder of the skeletal dysplasia type.

Ellis–van Creveld syndrome often is the result of founder effects in isolated human populations, such as the Amish and some small island inhabitants. Although relatively rare, this disorder does occur with higher incidence within founder-effect populations due to lack of genetic variability. Observation of the inheritance pattern has illustrated that the disease is autosomal recessive, meaning that both parents have to carry the gene in order for an individual to be affected by the disorder.

Ellis–van Creveld syndrome is caused by a mutation in the "EVC" gene, as well as by a mutation in a nonhomologous gene, "EVC2", located close to the EVC gene in a head-to-head configuration. The gene was identified by positional cloning. The EVC gene maps to the chromosome 4 short arm (4p16). The function of a healthy EVC gene is not well understood at this time.

Life expectancy for individuals with hypochondroplasia is normal; the maximum height is about 147 cm or 4.8 ft.

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 terms of cause this disorder is transmitted as an autosomal dominant trait affecting the "FGFR3" gene on chromosome 4p16.3, there is currently no cure for this condition.

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.

Spondyloepimetaphyseal dysplasia, Pakistani type is a form of spondyloepimetaphyseal dysplasia involving "PAPSS2" (also known as "ATPSK2"). The condition is rare.

Multiple epiphyseal dysplasia (MED) encompasses a spectrum of skeletal disorders, most of which are inherited in an autosomal dominant form. However, there is an autosomal recessive form.

Associated genes include COL9A1, COL9A2, COL9A3, COMP, and MATN3.

Types include:

Hypertension and brachydactyly syndrome (HTNB) also known as Bilginturan syndrome and brachydactyly type E among others is a very rare genetic disorder.

It was first reported in 1973 by N. Bilginturan et al. The estimated prevalence is less than 1 out of 1,000,000.

With so few described cases, establishing the basic pathophysiological mechanisms or genetic abnormalities has not been possible.

Lenz–Majewski syndrome is a skin condition characterized by hyperostosis, craniodiaphyseal dysplasia, dwarfism, cutis laxa, proximal symphalangism, syndactyly, brachydactyly, mental retardation, enamel hypoplasia, and hypertelorism.

In 2013, whole-exome sequencing showed that a missense mutation resulting in overactive phosphatidylserine synthase 1 was the cause of LMS, making it the first known human disease to be caused by disrupted phosphatidylserine metabolism. The researchers suggested a link between the condition and bone metabolism.

Nasodigitoacoustic syndrome, also called Keipert syndrome, is a rare congenital syndrome first described by J.A. Keipert and colleagues in 1973. The syndrome is characterized by a mishaped nose, broad thumbs and halluces (the big toes), brachydactyly, sensorineural hearing loss, facial features such as hypertelorism (unusually wide-set eyes), and developmental delay. It is believed to be inherited in an X-linked recessive manner, which means a genetic mutation causing the disorder is located on the X chromosome, and while two copies of the mutated gene must be inherited for a female to be born with the disorder, just one copy is sufficient to cause a male to be born with the disorder. Nasodigitoacoustic syndrome is likely caused by a mutated gene located on the X chromosome between positions Xq22.2–q28. The incidence of the syndrome has not been determined, but it is considered to affect less than 200,000 people in the United States, and no greater than 1 per 2,000 in Europe. It is similar to Keutel, Muenke, Rubinstein and Teunissen-Cremers syndrome.

In the above brachydactyly syndromes, short digits are the most prominent of the anomalies, but in many other syndromes (Down syndrome, Rubinstein-Taybi syndrome, etc.), brachydactyly is a minor feature compared to the other anomalies or problems comprising the syndrome.

Radiographic features include delayed epiphyseal ossification at the hips and knees, platyspondyly with irregular end plates and narrowed joint spaces, diffuse early osteoarthritic changes (in the spine and hands), mild brachydactyly and mild metaphyseal abnormalities which predominantly involve the hips and knees.

Fitzsimmons–Guilbert syndrome is an extremely rare genetic disease characterized by a slowly progressive spastic paraplegia, skeletal anomalies of the hands and feet with brachydactyly type E, cone-shaped epiphyses, abnormal metaphyseal–phalangeal pattern profile, sternal anomaly (pectus carinatum or excavatum), dysarthria, and mild intellectual deficit.

Ectrodactyly can be caused by various changes to 7q. When 7q is altered by a deletion or a translocation ectrodactyly can sometimes be associated with hearing loss. Ectrodactyly, or Split hand/split foot malformation (SHFM) type 1 is the only form of split hand/ malformation associated with sensorineural hearing loss.

A large number of human gene defects can cause ectrodactyly. The most common mode of inheritance is autosomal dominant with reduced penetrance, while autosomal recessive and X-linked forms occur more rarely. Ectrodactyly can also be caused by a duplication on 10q24. Detailed studies of a number of mouse models for ectrodactyly have also revealed that a failure to maintain median apical ectodermal ridge (AER) signalling can be the main pathogenic mechanism in triggering this abnormality.

A number of factors make the identification of the genetic defects underlying human ectrodactyly a complicated process: the limited number of families linked to each split hand/foot malformation (SHFM) locus, the large number of morphogens involved in limb development, the complex interactions between these morphogens, the involvement of modifier genes, and the presumed involvement of multiple gene or long-range regulatory elements in some cases of ectrodactyly. In the clinical setting these genetic characteristics can become problematic and making predictions of carrier status and severity of the disease impossible to predict.

In 2011, a novel mutation in DLX5 was found to be involved in SHFM.

Ectrodactyly is frequently seen with other congenital anomalies. Syndromes in which ectrodactyly is associated with other abnormalities can occur when two or more genes are affected by a chromosomal rearrangement. Disorders associated with ectrodactyly include Ectrodactyly-Ectodermal Dysplasia-Clefting (EEC) syndrome, which is closely correlated to the ADULT syndrome and Limb-mammary (LMS) syndrome, Ectrodactyly-Cleft Palate (ECP) syndrome, Ectrodactyly-Ectodermal Dysplasia-Macular Dystrophy syndrome, Ectrodactyly-Fibular Aplasia/Hypoplasia (EFA) syndrome, and Ectrodactyly-Polydactyly. More than 50 syndromes and associations involving ectrodactyly are distinguished in the London Dysmorphology Database.

A number of features found with Nasodigitoacoustic syndrome can be managed or treated. Sensorineural hearing loss in humans may be caused by a loss of hair cells (sensory receptors in the inner ear that are associated with hearing). This can be hereditary and/or within a syndrome, as is the case with nasodigitoacoustic syndrome, or attributed to infections such as viruses. For the management of sensorineural hearing loss, hearing aids have been used. Treatments, depending upon the cause and severity, may include a pharmacological approach (i.e., the use of certain steroids), or surgical intervention, like a cochlear implant.

Pulmonary, or pulmonic stenosis is an often congenital narrowing of the pulmonary valve; it can be present in nasodigitoacoustic-affected infants. Treatment of this cardiac abnormality can require surgery, or non-surgical procedures like balloon valvuloplasty (widening the valve with a balloon catheter).

Majewski's polydactyly syndrome, also known as polydactyly with neonatal chondrodystrophy type I, short rib-polydactyly syndrome type II, and short rib-polydactyly syndrome, is a lethal form of neonatal dwarfism characterized by osteochondrodysplasia (skeletal abnormalities in the development of bone and cartilage) with a narrow thorax, polysyndactyly, disproportionately short tibiae, thorax dysplasia, hypoplastic lungs and respiratory insufficiency. Associated anomalies include protruding abdomen, brachydactyly, peculiar faces, hypoplastic epiglottis, cardiovascular defects, renal cysts, and also genital anomalies. Death occurs before or at birth.

The disease is inherited in an autosomal recessive pattern.

It was characterized in 1971.

Thumb hypoplasia is a spectrum of congenital abnormalities of the thumb varying from small defects to absolute retardation of the thumb. It can be isolated, when only the thumb is affected, and in 60% of the cases it is associated with radial dysplasia (or radial club, radius dysplasia, longitudinal radial deficiency). Radial dysplasia is the condition in which the forearm bone and the soft tissues on the thumb side are underdeveloped or absent.

In an embryo the upper extremities develop from week four of the gestation. During the fifth to eighth week the thumb will further develop. In this period something goes wrong with the growth of the thumb but the exact cause of thumb hypoplasia is unknown.

One out of every 100,000 live births shows thumb hypoplasia. In more than 50% of the cases both hands are affected, otherwise mainly the right hand is affected.

About 86% of the children with hypoplastic thumb have associated abnormalities. Embryological hand development occurs simultaneously with growth and development of the cardiovascular, neurologic and hematopoietic systems. Thumb hypoplasia has been described in 30 syndromes wherein those abnormalities have been seen. A syndrome is a combination of three or more abnormalities. Examples of syndromes with an hypoplastic thumb are Holt-Oram syndrome, VACTERL association and thrombocytopenia absent radius (TAR syndrome).

Aarskog–Scott syndrome is a rare disease inherited as X-linked and characterized by short stature, facial abnormalities, skeletal and genital anomalies. This condition mainly affects males, although females may have mild features of the syndrome.

The Aarskog–Scott syndrome (AAS) is also known as the Aarskog syndrome, faciodigitogenital syndrome, shawl scrotum syndrome and faciogenital dysplasia.