The hallmark of the condition is a sunken appearance of the sternum. The most common form is a cup-shaped concavity, involving the lower end of the sternum; also a broader concavity involving the upper costal cartilages is possible. The lower-most ribs may protrude ("flared ribs"). Pectus excavatum defects may be symmetric or asymmetric.

People may also experience chest and back pain, which is usually of musculoskeletal origin.

In mild cases, cardiorespiratory function is normal, although the heart can be displaced and/or rotated. In severe cases, mitral valve prolapse may be present and physical capability may be limited due to base lung capacity being decreased.

Psychological symptoms manifest with feelings of embarrassment, social anxiety, shame, limited capacity for activities and communication, negativity, intolerance, frustration, and even depression.

People with pectus carinatum usually develop normal hearts and lungs, but the malformation may prevent these from functioning optimally. In moderate to severe cases of pectus carinatum, the chest wall is rigidly held in an outward position. Thus, respirations are inefficient and the individual needs to use the accessory muscles for respiration, rather than normal chest muscles, during strenuous exercise. This negatively affects gas exchange and causes a decrease in stamina. Children with pectus malformations often tire sooner than their peers, due to shortness of breath and fatigue. Commonly concurrent is mild to moderate asthma.

Some children with pectus carinatum also have scoliosis (i.e., curvature of the spine). Some have mitral valve prolapse, a condition in which the heart mitral valve functions abnormally. Connective tissue disorders involving structural abnormalities of the major blood vessels and heart valves are also seen. Although rarely seen, some children have other connective tissue disorders, including arthritis, visual impairment and healing impairment.

Apart from the possible physiologic consequences, pectus malformations can have a significant psychologic impact. Some people, especially those with milder cases, live happily with pectus carinatum. For others, though, the shape of the chest can damage their self-image and confidence, possibly disrupting social connections and causing them to feel uncomfortable throughout adolescence and adulthood. As the child grows older, bodybuilding techniques may be useful for balancing visual impact.

A less common variant of pectus carinatum is "pectus arcuatum" (also called type 2 pectus excavatum, chondromanubrial malformation or Currarino–Silverman syndrome or pouter pigeon malformation), which produces a manubrial and upper sternal protrusion, particularly also at the sternal angle. Pectus arcuatum is often confused with a combination of pectus carinatum and pectus excavatum, but in pectus arcuatum the visual appearance is characterized by a protrusion of the costal cartilages and there is no depression of the sternum.

Pectus carinatum is an overgrowth of costal cartilage causing the sternum to protrude forward. It primarily occurs among four different patient groups, and males are more frequently affected than females. Most commonly, pectus carinatum develops in 11-to-14-year-old pubertal males undergoing a growth spurt. Some parents report that their child's pectus carinatum seemingly popped up overnight. Second most common is the presence of pectus carinatum at or shortly after birth. The condition may be evident in newborns as a rounded anterior chest wall. As the child reaches age 2 or 3 years of age, the outward sternal protrusion becomes more pronounced. Pectus carinatum can also be caused by vitamin D deficiency in children (Rickets) due to deposition of unmineralized osteoid. Least common is a pectus carinatum malformation following open-heart surgery or in children with poorly controlled bronchial asthma.

Pectus carinatum is generally a solitary, non-syndromic abnormality. However, the condition may be present in association with other syndromes: Turner syndrome, Noonan syndrome, Loeys-Dietz syndrome, Marfan syndrome, Ehlers-Danlos syndrome, Morquio syndrome, trisomy 18, trisomy 21, homocystinuria, osteogenesis imperfecta, multiple lentigines syndrome (LEOPARD syndrome), Sly syndrome (mucopolysaccharidosis type VII), and scoliosis.

In about 25% of cases of pectus carinatum, the patient has a family member with the condition.

Pectus excavatum is a congenital deformity of the anterior thoracic wall in which the sternum and rib cage grow abnormally. This produces a caved-in or sunken appearance of the chest. It can either be present at birth or not develop until puberty.

Pectus excavatum is sometimes considered to be cosmetic, but depending on the severity, it can impair cardiac and respiratory function and cause pain in the chest and back.

People with the condition may experience negative psychosocial effects, and avoid activities that expose the chest in some societies.

Radial aplasia is a congenital defect which affects the formation of the radius bone in the arm. The radius is the lateral bone which connects to the wrist via articulation with the carpal bones. A child born with this condition has either a short or absent radius bone in one or both of his or her arm(s). Radial aplasia also results in the thumb being either partly formed or completely absent from the hand. Radial aplasia is connected with the condition VACTERL association. The cause for radial aplasia in unknown, but it widely believed to occur within the first ten weeks of gestation.

The differential diagnosis includes;

- Symbrachydactyly

- Chorionic villus sampling

- Congenital amputations

- Hypoplasias of hand, digit, thumb

- Adams-Oliver syndrome

- ADAM complex

ADAM Complex; CRS is sometimes mislabeled as ADAM complex. ADAM is an abbreviation for Amniotic Deformity, Adhesions Mutilations. CRS is the malformation due to a constriction ring around mostly a limb. ADAM-complex is the association of limb defects (caused by constriction rings) and certain craniofacial clefts

“Adams-Oliver syndrome is often mislabeled as CRS and consists of cutis aplasia of the scalp in which a longitudinal defect can vary in size and can often be associated with full-thickness skullcap loss. The distal digital or toe hypoplasia-aplasia is often confused with CRS. Constriction rings with or without edema are not present. The digital or toe hypoplasia-aplasia usually contains diminutive nails or nail folds”.

The diagnosis of constriction ring syndrome can be confirmed with an ultrasonography. The clinical manifestations can be extremely variable. It could be a single or multiple manifestation. This can be confirmed at the end of the first trimester or at the beginning of the second trimester. But not every patient will be diagnosed at that moment, most will get this diagnosis at birth.

A bifid rib (bifurcated rib or sternum bifidum) is a congenital abnormality of the rib cage and associated muscles and nerves which occurs in about 1.2% of humans. Bifid ribs occur in up to 8.4% of Samoans. The sternal end of the rib is cleaved into two. It is usually unilateral.

Bifid ribs are usually asymptomatic, and are often discovered incidentally by chest X-ray. Effects of this neuroskeletal anomaly can include respiratory difficulties, neurological difficulties, limitations, and limited energy from the stress of needing to compensate for the neurophysiological difficulties. Another association is with odontogenic keratocysts (OKC [a.k.a keratocystic odontogenic tumor (WHO terminology)]) of the jaw which may behave aggressively and have a high propensity to recur when treated with simple enucleation and curettage. When seen together, the patient is likely to have Nevoid Basal Cell Carcinoma Syndrome (a.k.a. Gorlin-Goltz syndrome) and should be evaluated with this in mind.

Dysmelia (from Gr. δυσ- "dys", "bad" + μέλ|ος "mél|os", "limb" + Eng. suff. -ia) is a congenital disorder of a limb resulting from a disturbance in embryonic development.

The skeletal structures of individuals who have this disorder may have pronounced deformities. As reported by several medical doctors, the following features are commonly found in people who suffer from nail–patella syndrome:

Bones and joints

- Patellar involvement is present in approximately 90% of patients; however, patellar aplasia occurs in only 20%.

- In instances in which the patellae are smaller or luxated, the knees may be unstable.

- The elbows may have limited motion (e.g., limited pronation, supination, extension).

- Subluxation of the radial head may occur.

- Arthrodysplasia of the elbows is reported in approximately 90% of patients.

- General hyperextension of the joints can be present.

- Exostoses arising from the posterior aspect of the iliac bones ("iliac horns") are present in as many as 80% of patients; this finding is considered pathognomonic for the syndrome.

- Other reported bone changes include scoliosis, scapular hypoplasia, and the presence of cervical ribs.

Kidney issues may arise such as proteinuria and nephritis. Proteinuria is usually the first sign of renal involvement and either rapidly or years after suffering from asymptomatic proteinuria, renal failure occurs in around 5% of NPS patients. Hypothyroidism, irritable bowel syndrome, attention deficit hyperactivity disorder (ADHD), and thin tooth enamel are associated with NPS, but whether these are related or simply coincidences are unclear.

Clinically and radiologically the disease is characterized by severe shortening of long bones (limb's both proximal and median segments are affected), aplasia or severe hypoplasia of ulna and fibula, thickened and curved radius and tibia. These anomalies can cause deformities of the hands and feet. Hypoplasia of the mandible can also be present.

Dysmelia can refer to

- missing (aplasia) limbs: amelia, oligodactyly, congenital amputation e.g. Tibial or Radial aplasia

- malformation of limbs: shortening (micromelia, rhizomelia or mesomelia), ectrodactyly, phocomelia, meromelia, syndactyly, brachydactyly, club foot

- too many limbs: polymelia, polydactyly, polysyndactyly

- others: Tetraamelia, hemimelia, Symbrachydactyly

Clinical expressions of PPS are highly variable, but include the following:

- Limb findings: an extensive web running from behind the knee down to the heel (90%), malformed toenails, and webbed toes.

- Facial findings: cleft palate with or without cleft lip (75%), pits in the lower lip (40%), and fibrous bands in the mouth known as syngnathia (25%).

- Genital findings (50%): hypoplasia of the labia majora, malformation of the scrotum, and cryptorchidism.

Two key features of AOS are aplasia cutis congenita with or without underlying bony defects and terminal transverse limb defects. Cutis aplasia congenita is defined as missing skin over any area of the body at birth; in AOS skin aplasia occurs at the vertex of the skull. The size of the lesion is variable and may range from solitary round hairless patches to complete exposure of the cranial contents. There are also varying degrees of terminal limb defects (for example, shortened digits) of the upper extremities, lower extremities, or both. Individuals with AOS may have mild growth deficiency, with height in the low-normal percentiles. The skin is frequently observed to have a mottled appearance (cutis marmorata telangiectatica congenita). Other congenital anomalies, including cardiovascular malformations, cleft lip and/or palate, abnormal renal system, and neurologic disorders manifesting as seizure disorders and developmental delay are sometimes observed. Variable defects in blood vessels have been described, including hypoplastic aortic arch, middle cerebral artery, pulmonary arteries. Other vascular abnormalities described in AOS include absent portal vein, portal sclerosis, arteriovenous malformations, abnormal umbilical veins, and dilated renal veins.

The syndrome has five characteristic findings:

- Omphalocele

- Anterior diaphragmatic hernia

- Sternal cleft with or without ectopia cordis

- Diaphragmatic pericardium defects (no diaphragmatic pericardium)

- Intracardiac defect: ventricular septal defect, diverticulum of the left ventricle, Tetralogy of Fallot

The key affected features of this condition are described in its name.

Scalp: There are raised nodules over the posterior aspect of the scalp, covered by scarred non-hair bearing skin.

Ears: The shape of the pinnae is abnormal, with the superior edge of the pinna being turned over more than usual. The size of the tragus, antitragus and lobule may be small.

Nipples: The nipples are absent or rudimentary. The breasts may be small or virtually absent.

Other features of the condition include:

Dental abnormalities: missing or widely spaced teeth

Syndactyly: toes or fingers may be partially joined proximally

Renal abnormalities: renal hypoplasia, pyeloureteral duplication

Eye abnormalities: Cataract, coloboma of the iris and asymmetric pupils.

Michels Caskey syndrome is a rare disorder that combines spinal and skeletal abnormalities, especially of the thumbs, with abnormal or absent female reproductive organs. Examples include the absence of a cervix and upper vagina or abnormalities of the uterus or vagina. Symptoms may also include scoliosis and primary amenorrhea. Synonyms include Mullerian aplasia with hypoplastic thumbs, hypoplastic thumb Mullerian aplasia, and Mullerian aplasia with unilateral hypoplasia of the thumbs and skeletal spine deformities.

Causes include:

- Rickets : Nodularity at costochondral junction (rachitic rosary).

- Scurvy : More angular costochondral junction with a sharper step-off (scorbutic rosary) and depressed sternum.

- Chondrodystrophy

A squitten is a cat with unusually short forelegs and/or unusually long hind legs that resembles a squirrel. It is an example of a cat body type genetic mutation. The word is a portmanteau of squirrel and kitten.

The term kangaroo cat is also, rarely, used; this derives from a 1953 specimen known as the Stalingrad Kangaroo Cat.

Hemimelia comprises

- Fibular hemimelia, Congenital longitudinal deficiency of the fibula or Fibular longitudinal meromelia

- Tibial hemimelia, Congenital longitudenal deficiency of the tibia, Congenital aplasia and dysplasia of the tibia with intact fibula, Congenital longitudinal deficiency of the tibia or Tibial longitudinal meromelia

- Radial Hemimelia, Congenital longitudinal deficiency of the radius, Radial clubhand, Radial longitudinal meromelia or Radial ray agenesis

- Ulnar hemimelia, Congenital longitudinal deficiency of the ulna, Ulnar clubhand or Ulnar longitudinal meromelia

Aphalangy, hemivertebrae and urogenital-intestinal dysgenesis is an extremely rare syndrome, described only in three siblings. It associates hypoplasia or aplasia of phalanges of hands and feet, hemivertebrae and various urogenital and/or intestinal abnormalities. Intrafamilial variability is important as one sister had lethal abnormalities (Potter sequence and pulmonary hypoplasia), while her affected brother was in good health with normal psychomotor development at 6 months of age. Prognosis seems to depend mainly on the severity of visceral malformations. Etiology and inheritance remain unknown.

It's part of the mesomelic and rhizomelic skeletal dysplasias, primary bone diseases in which the short stature is due to a lack of complete bone development of the limb's long bones.

It's strictly related to another disease, the Léri–Weill dyschondrosteosis, of which it seems to be the homozygothic variant, clinically more severe (it differs from this disorder for the absence, in some cases, of the Madelung deformity too).

Nail–patella syndrome (NPS) (also known as "HOOD syndrome") is a genetic disorder that results in small, poorly developed nails and kneecaps, but can also affect many other areas of the body, such as the elbows, chest, and hips. The name "nail–patella" can be very misleading because the syndrome often affects many other areas of the body, including even the production of certain proteins. Those affected by NPS may have one or more affected areas of the body, and its severity varies depending on the individual. It is also referred to as iliac horn syndrome, hereditary onychoosteodysplasia (HOOD syndrome), Fong disease or Turner–Kieser syndrome.

Diagnosis of NPS can be made at birth, but is common for it to remain undiagnosed for several generations. While there is no cure available for NPS, treatment is available and recommended.

The most common and defining features of BGS are craniosynostosis and radial ray deficiency. The observations of these features allow for a diagnosis of BGS to be made, as these symptoms characterize the syndrome. Craniosynostosis involves the pre-mature fusion of bones in the skull. The coronal craniosynostosis that is commonly seen in patients with BGS results in the fusion of the skull along the coronal suture. Because of the changes in how the bones of the skull are connected together, people with BGS will have an abnormally shaped head, known as brachycephaly. Features commonly seen in those with coronal craniosynostosis are bulging eyes, shallow eye pockets, and a prominent forehead. Radial ray deficiency is another clinical characteristic of those with BGS, and results in the under-development (hypoplasia) or the absence (aplasia) of the bones in the arms and the hands. These bones include the radius, the carpal bones associated with the radius and the thumb. Oligodactyly can also result from radial ray deficiency, meaning that someone with BGS may have fewer than five fingers. Radial ray deficiency that is associated with syndromes (such as BGS) occurs bi-laterally, affecting both arms.

Some of the other clinical characteristics sometimes associated with this disorder are growth retardation and poikiloderma. Although the presentation of BGS may differ between individuals, these characteristics are often observed. People with BGS may have stunted growth, short stature and misshapen kneecaps. Poikiloderma may also be present in people with this syndrome, meaning that their skin may have regions of hyperpigmentation and hypopigmentation, or regions where the skin is missing (atrophy).

Popliteal pterygium syndrome (PPS) is an inherited condition affecting the face, limbs, and genitalia. The syndrome goes by a number of names including the "popliteal web syndrome" and, more inclusively, the "facio-genito-popliteal syndrome". The term PPS was coined by Gorlin "et al.." in 1968 on the basis of the most unusual anomaly, the popliteal pterygium (a web behind the knee).