Robinow noted the resemblance of affected patients' faces to that of a fetus, using the term "fetal facies" to describe the appearance of a small face and widely spaced eyes. Clinical features also may include a short, upturned nose, a prominent forehead, and a flat nasal bridge. The upper lip may be "tented", exposing dental crowding, "tongue tie", or gum hypertrophy.

Though the eyes do not protrude, abnormalities in the lower eyelid may give that impression. Surgery may be necessary if the eyes cannot close fully. In addition, the ears may be set low on the head or have a deformed pinna.

Patients suffer from dwarfism, short lower arms, small feet, and small hands. Fingers and toes may also be abnormally short and laterally or medially bent. The thumb may be displaced and some patients, notably in Turkey, experience ectrodactyly. All patients often suffer from vertebral segmentation abnormalities. Those with the dominant variant have, at most, a single butterfly vertebra. Those with the recessive form, however, may suffer from hemivertebrae, vertebral fusion, and rib anomalies. Some cases resemble Jarcho-Levin syndrome or spondylocostal dysostosis.

Genital defects characteristically seen in males include a micropenis with a normally developed scrotum and testes. Sometimes, testicles may be undescended, or the patient may suffer from hypospadias. Female genital defects may include a reduced size clitoris and underdeveloped labia minora. Infrequently, the labia majora may also be underdeveloped. Some research has shown that females may experience vaginal atresia or haematocolpos.

The autosomal recessive form of the disorder tends to be much more severe. Examples of differences are summarized in the following table:

Very frequent signs

- Abnormal gastrointestinal tract

- Absent pectoral muscles

- Brachydactyly (Short fingers)

- Dextrocardia

- Diaphragmatic hernia/defect

- Humerus absent/abnormal

- Liver/biliary tract anomalies

- Maternal diabetes

- Oligodactyly/missing fingers

- Radius absent/abnormal

- Rhizomelic micromelia (relatively shorter proximal segment of the limbs compared to the middle and the distal segments)

- Sparsity or abnormality of axillary hair on affected side

- Syndactyly of fingers (webbing)

- Ulna absent/abnormal

- Upper limb asymmetry

- Abnormal rib

- Simian crease on affected side

Frequent signs

- Hypoplastic/absent nipples

- Scapula anomaly

Occasional signs

- Agenesis/hypoplasia of kidneys

- Encephalocele/exencephaly

- Abnormal morphology of hypothalamic-hypophyseal axis

- Abnormal function of hypothalamic-hypophyseal axis

- Microcephaly

- Preaxial polydactyly

- Ureteric anomalies (reflux/duplex system)

- Vertebral segmentation anomaly

Cleidocranial dysostosis is a general skeletal condition so named from the collarbone (cleido-) and cranium deformities which people with it often have.

People with the condition usually present with a painless swelling in the area of the clavicles at 2–3 years of age. Common features are:

- Clavicles (collarbones) can be partly missing leaving only the medial part of the bone. In 10% cases, they are completely missing. If the collarbones are completely missing or reduced to small vestiges, this allows hypermobility of the shoulders including ability to touch the shoulders together in front of the chest. The defect is bilateral 80% of the time. Partial collarbones may cause nerve damage symptoms and therefore have to be removed by surgery.

- The mandible is prognathic due to hypoplasia of maxilla (micrognathism) and other facial bones.

- A soft spot or larger soft area in the top of the head where the fontanelle failed to close, or the fontanelle closes late.

- Bones and joints are underdeveloped. People are shorter and their frames are smaller than their siblings who do not have the condition.

- The permanent teeth include supernumerary teeth. Unless these supernumeraries are removed they will crowd the adult teeth in what already may be an underdeveloped jaw. If so, the supernumeraries will probably need to be removed to make space for the adult teeth. Up to 13 supernumarary teeth have been observed. Teeth may also be displaced. Cementum formation may be deficient.

- Failure of eruption of permanent teeth.

- Bossing (bulging) of the forehead.

- Open skull sutures, large fontanelles.

- Hypertelorism.

- Delayed ossification of bones forming symphysis pubis, producing a widened symphysis.

- Coxa vara can occur, limiting abduction and causing Trendelenburg gait.

- Short middle fifth phalanges, sometimes causing short and wide fingers.

- Vertebral abnormalities.

- On rare occasions, brachial plexus irritation can occur.

- Scoliosis, spina bifida and syringomyelia have also been described.

Other features are: parietal bossing, basilar invagination (atlantoaxial impaction), persistent metopic suture, abnormal ear structures with hearing loss, supernumerary ribs, hemivertebrae with spondylosis, small and high scapulae, hypoplasia of illiac bones, absence of the pubic bone, short / absent fibular bones, short / absent radial bones, hypoplastic terminal phalanges.

The Pai Syndrome is a rare subtype of frontonasal dysplasia. It is a triad of developmental defects of the face, comprising midline cleft of the upper lip, nasal and facial skin polyps and central nervous system lipomas. When all the cases are compared, a difference in severity of the midline cleft of the upper lip can be seen. The mild form presents with just a gap between the upper teeth. The severe group presents with a complete cleft of the upper lip and alveolar ridge.

Nervous system lipomas are rare congenital benign tumors of the central nervous system, mostly located in the medial line and especially in the corpus callosum. Generally, patients with these lipomas present with strokes. However, patients with the Pai syndrome don’t. That is why it is suggested that isolated nervous system lipomas have a different embryological origin than the lipomas present in the Pai syndrome. The treatment of CNS lipomas mainly consists of observation and follow up.

Skin lipomas occur relatively often in the normal population. However, facial and nasal lipomas are rare, especially in childhood. However, the Pai syndrome often present with facial and nasal polyps. These skin lipomas are benign, and are therefore more a cosmetic problem than a functional problem.

The skin lipomas can develop on different parts of the face. The most common place is the nose. Other common places are the forehead, the conjunctivae and the frenulum linguae. The amount of skin lipomas is not related to the severity of the midline clefting.

Patients with the Pai syndrome have a normal neuropsychological development.

Until today there is no known cause for the Pai syndrome.

The large variety in phenotypes make the Pai syndrome difficult to diagnose. Thus the incidence of Pai syndrome seems to be underestimated.

Specific types of additional body parts include:

- Accessory breast – one or more additional breasts

- Accessory spleen – one or more additional spleens

- Cervical rib – an additional rib

- Diphallia - Having two penes/penises.

- Hermaphroditism – having both sexes' sex organs

- Hyperdontia – additional teeth

- Pelvic digit – a bony growth in the soft tissue of the pelvic region

- Polycephaly – an extra head

- Polydactyly – additional fingers or toes

- Polymelia — an extra arm or leg.

- Polyorchidism – having three or more testicles

- Supernumerary bones – these additional bones are fairly common, particularly in the feet, and are frequently mistaken for fractures on x-rays.

- Supernumerary kidney – a third kidney

- Supernumerary nipples – an additional nipple

- Supernumerary phantom limbs – where the brain acts as though a limb were there, but it is not.

- Syndactyly – webbing between the fingers or toes

- Uterus didelphys – two vaginal canals and/or uteri

It involves numerous anomalies including:

- Post-axial polydactyly

- Congenital heart defects (most commonly an atrial septal defect producing a common atrium, occurring in 60% of affected individuals)

- Teeth present at birth (natal teeth)

- Fingernail dysplasia

- Short-limbed dwarfism, mesomelic pattern

- Short ribs

- Cleft palate

- Malformation of the wrist bones (fusion of the hamate and capitate bones).

Infants with this condition have disproportionately short arms and legs with extra folds of skin. Other signs of the disorder include a narrow chest, small ribs, underdeveloped lungs, and an enlarged head with a large forehead and prominent, wide-spaced eyes.

Thanatophoric dysplasia is a lethal skeletal dysplasia divided into two subtypes. Type I is characterized by extreme rhizomelia, bowed long bones, narrow thorax, a relatively large head, normal trunk length and absent cloverleaf skull. The spine shows platyspondyly, the cranium has a short base, and, frequently, the foramen magnum is decreased in size. The forehead is prominent, and hypertelorism and a saddle nose may be present. Hands and feet are normal, but fingers are short. Type II is characterized by short, straight long bones and cloverleaf skull.

It presents with typical telephone handled shaped long bones and a H-shaped vertebrae.

While the definitive presentation of the disease is a patient having bowed lower limbs and sex reversal in 46,XY males, there are other clinical criteria that can be used, absent these characteristics, to make the diagnosis. Patients may present with underdeveloped shoulder blades, shortened and angulated lower limbs, a vertically oriented and narrow pelvis, an enlarged head, an undersized jaw, cleft palate, flat nasal bridge, low set ears, club feet, dislocated hips, 11 pairs of ribs instead of 12, or bone abnormalities in the neck and spine. Respiratory distress can be caused by an underdeveloped trachea which collapses on inhalation or by insufficient rib cage development.

Robinow syndrome is an extremely rare genetic disorder characterized by short-limbed dwarfism, abnormalities in the head, face, and external genitalia, as well as vertebral segmentation. The disorder was first described in 1969 by human geneticist Meinhard Robinow, along with physicians Frederic N. Silverman and Hugo D. Smith, in the "American Journal of Diseases of Children". By 2002, over 100 cases had been documented and introduced into medical literature.

Two forms of the disorder exist, dominant and recessive, of which the former is more common. Patients with the dominant version often suffer moderately from the aforementioned symptoms. Recessive cases, on the other hand, are usually more physically marked, and individuals may exhibit more skeletal abnormalities. The recessive form is particularly frequent in Turkey. However, this can likely be explained by a common ancestor, as these patients' families can be traced to a single town in Eastern Turkey. Clusters of the autosomal recessive form have also been documented in Oman and Czechoslovakia.

The syndrome is also known as Robinow-Silverman-Smith syndrome, Robinow dwarfism, fetal face, fetal face syndrome, fetal facies syndrome, acral dysostosis with facial and genital abnormalities, or mesomelic dwarfism-small genitalia syndrome. The recessive form was previously known as Covesdem syndrome.

This classification is based on the morphologic characteristics of FND, that describes a variety of phenotypes

Both of these classifications are further described in table 1. This table originates from the article ‘Acromelic frontonasal dysplasia: further delineation of a subtype with brain malformations and polydactyly (Toriello syndrome)', Verloes et al.

Campomelic dysplasia (CMD) is a rare genetic disorder characterized by bowing of the long bones and many other skeletal and extraskeletal features.

It is frequently lethal in the neonatal period due to respiratory insufficiency, but the severity of the disease is variable, and some patients survive into adulthood.

The name is derived from the Greek roots "campo" (or "campto"), meaning bent, and "melia", meaning limb.

An unusual aspect of the disease is that up to two-thirds of affected 46,XY genotypic males display a range of Disorders of Sexual Development (DSD) and genital ambiguities or may even develop as normal phenotypic females as in complete 46 XY sex reversal.

An atypical form of the disease with absence of bowed limbs is called, prosaically, acampomelic campomelic dysplasia (ACD) and is found in about 10% of patients, particularly those surviving the neonatal period.

Polydactyly or polydactylism (), also known as hyperdactyly, is a congenital physical anomaly in humans, dogs, and cats having supernumerary fingers or toes.

Polydactyly is the opposite of oligodactyly (fewer fingers or toes).

Infants with type 1 thanatophoric dysplasia also have curved thigh bones, flattened bones of the spine (platyspondyly) and shortened thoracic ribs. Note: Prenatal ultra-sound images of the ribs sometimes appear asymmetrical when in fact they are not. In certain cases, this has caused a misdiagnosis of Osteogenisis Imperfecta (OI) type II.

An unusual head shape called kleeblattschädel ("cloverleaf skull") can be seen with type 2 thanatophoric dysplasia.

This is a very rare situation, in which the extra digit is on the ring, middle or index finger. Of these fingers, the index finger is most often affected, whereas the ring finger is rarely affected.

This type of polydactyly can be associated with syndactyly, cleft hand and several syndromes.

Polysyndactyly presents various degrees of syndactyly affecting fingers three and four.

This condition is a skeletal dysplasia characterized by short stature, mild brachydactyly, kyphoscoliosis, abnormal gait, enlarged knee joints, precocious osteoarthropathy, platyspondyly, delayed epiphyseal ossification, mild metaphyseal abnormalities, short stature and short and bowed legs. Intelligence is normal.

Some patients may manifest premature pubarche and hyperandrogenism.

Other features that may form part of the syndrome include precocious costal calcification, small iliac bones, short femoral necks, coxa vara, short halluces and fused vertebral bodies.

The following are symptoms characteristic with individuals having the disorder. Individuals may display some, most, or all of these symptoms throughout the course of their life, though symptoms may vary with each patient.

- Abnormal hair (coarse, thick, brittle)

- Calvarial hypomineralization (soft skull)

- Y-shaped cataracts by 1–2 years of age

- Skeletal defects

- Hypertelorism (wide-set eyes)

- Facial dysmorphisms

- Late-closing fontanels

- Abnormal accumulation of proteins in the endoplasmic reticulum

- Scoliosis

- Broad forehead, nose

- Missing, small teeth or abnormal teeth positioning

- Poor skull calcification

- Flat foot

- Motor delay

- Abnormal vertebrae

- Prominent forehead and brow

- High nose bridge

- Capillary hemangioma

- Delayed tooth eruption

- Long upper lip groove

- Large mouth

- High arched palate

- Narrow hips and rib cage

- Thin lips

- Narrow and sloping shoulders

- Hyperpigmentation

- Hyperextensible joints

Onset of the disease is in neonatal development and infancy, and symptoms tend to become evident soon after birth.

Supernumerary body parts are most commonly a congenital disorder involving the growth of an additional part of the body and a deviation from the body plan. Body parts may be easily visible or hidden away, such as internal organs.

Many additional body parts form by the same process as conjoined twins: the zygote begins to split but fails to completely separate. This condition may also be a symptom of repeated occurrences of continuous inbreeding in a genetic line.

Fibrochondrogenesis is a congenital disorder presenting several features and radiological findings, some which distinguish it from other osteochondrodysplasias. These include: fibroblastic dysplasia and fibrosis of chondrocytes (cells which form cartilage); and flared, widened

long bone metaphyses (the portion of bone that grows during childhood).

Other prominent features include dwarfism, shortened ribs that have a appearance, micrognathism (severely underdeveloped jaw), macrocephaly (enlarged head), thoracic hypoplasia (underdeveloped chest), enlarged stomach, platyspondyly (flattened spine), and the somewhat uncommon deformity of tongue (in which the tongue appears split, resembling that of a reptile).

Ectrodactyly, split hand, cleft hand, derived from the Greek "ektroma" (abortion) and "daktylos" (finger) involves the deficiency or absence of one or more central digits of the hand or foot and is also known as split hand/split foot malformation (SHFM). The hands and feet of people with ectrodactyly are often described as "claw-like" and may include only the thumb and one finger (usually either the little finger, ring finger, or a syndactyly of the two) with similar abnormalities of the feet.

It is a rare form of a congenital disorder in which the development of the hand is disturbed. It is a type I failure of formation – longitudinal arrest. The central ray of the hand is affected and usually appears without proximal deficiencies of nerves, vessels, tendons, muscles and bones in contrast to the radial and ulnar deficiencies. The cleft hand appears as a V-shaped cleft situated in the centre of the hand. The digits at the borders of the cleft might be syndactilyzed, and one or more digits can be absent. In most types, the thumb, ring finger and little finger are the less affected parts of the hand. The incidence of cleft hand varies from 1 in 90,000 to 1 in 10,000 births depending on the used classification. Cleft hand can appear unilateral or bilateral, and can appear isolated or associated with a syndrome.

Split hand/foot malformation (SHFM) is characterized by underdeveloped or absent central digital rays, clefts of hands and feet, and variable syndactyly of the remaining digits. SHFM is a heterogeneous condition caused by abnormalities at one of multiple loci, including SHFM1 (SHFM1 at 7q21-q22), SHFM2 (Xq26), SHFM3 (FBXW4/DACTYLIN at 10q24), SHFM4 (TP63 at 3q27), and SHFM5 (DLX1 and DLX 2 at 2q31). SHFM3 is unique in that it is caused by submicroscopic tandem chromosome duplications of FBXW4/DACTYLIN. SHFM3 is considered 'isolated' ectrodactyly and does not show a mutation of the tp63 gene.

Poland syndrome, named after British surgeon Alfred Poland, is a rare birth defect characterized by underdevelopment or absence of the chest muscle (pectoralis) on one side of the body, and usually also webbing of the fingers (cutaneous syndactyly) of the hand on the same side (the ipsilateral hand). In most affected individuals, the missing part is the large section of the muscle that normally attaches to the upper arm on one side and the breastbone (sternum) on the other. Other abnormalities may occur on the affected side of the torso. In some cases, additional muscles in the chest wall, side, and shoulder are missing or underdeveloped.

There may also be rib cage abnormalities, such as shortened ribs, and the ribs may be noticeable due to less fat under the skin (subcutaneous fat). Breast and nipple abnormalities may also occur, and underarm (axillary) hair is sometimes sparse or abnormally placed. In most cases, the abnormalities in the chest area do not cause health problems or affect movement. Poland syndrome most often affects the right side of the body, and occurs more often in males than in females.

It is usually considered a unilateral condition. Some have claimed that the term can be applied in bilateral presentation, but others recommend using alternate terminology in those cases.

EEM syndrome exhibits a combination of prominent symptoms and features. These include: ectodermal dysplasia (systemic malformations of ectodermal tissues), ectrodactyly ("lobster claw" deformity in the hands and feet), macular dystrophy (a progressive eye disease), syndactyly (webbed fingers or toes), hypotrichosis (a type of hair-loss), and dental abnormalities (hypodontia).

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.

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

Babies born with Jarcho-Levin may be very healthy and grow up to lead normal lives. However, many individuals with Jarcho-Levin suffer from problems of respiratory insufficiency secondary to volume-restricted thoraces. These individuals will often develop pulmonary complications and die in infancy or early childhood. The disparity in outcomes of those with the syndrome is related to the fact that Jarcho-Levin actually encompasses two or more distinct syndromes, each with its own range of prognoses. The syndromes currently recognized as subtypes of Jarcho-Levin are termed spondylothoracic dysplasia and spondylocostal dysostosis. The disease is related to the SRRT gene.

Spondylocostal dysostosis is a rare, heritable axial skeleton growth disorder. It is characterized by widespread and sometimes severe malformations of the vertebral column and ribs, shortened thorax, and moderate to severe scoliosis and kyphosis. Individuals with Jarcho-Levin typically appear to have a short trunk and neck, with arms appearing relatively long in comparison, and a slightly protuberant abdomen. Severely affected individuals may have life-threatening pulmonary complications due to deformities of the thorax. The syndrome was first described by Saul Jarcho and Paul M. Levin at Johns Hopkins University in 1938.