Collagen improperly formed, enough collagen is made but it is defective.

- Bones fracture easily, sometimes even before birth

- Bone deformity, often severe

- Respiratory problems possible

- Short stature, spinal curvature and sometimes barrel-shaped rib cage

- Triangular face

- Loose joints (double-jointed)

- Poor muscle tone in arms and legs

- Discolouration of the sclera (the 'whites' of the eyes are blue)

- Early loss of hearing possible

Type III is distinguished among the other classifications as being the "progressive deforming" type, wherein a neonate presents with mild symptoms at birth and develops the aforementioned symptoms throughout life. Lifespans may be normal, albeit with severe physical handicapping.

Collagen quantity is sufficient but is not of a high enough quality

- Bones fracture easily, especially before puberty

- Short stature, spinal curvature, and barrel-shaped rib cage

- Bone deformity is mild to moderate

- Early loss of hearing

Similar to Type I, Type IV can be further subclassified into types IVA and IVB characterized by absence (IVA) or presence (IVB) of dentinogenesis imperfecta.

"Maffucci syndrome" is a sporadic disease characterized by the presence of multiple enchondromas associated with multiple simple or cavernous soft tissue hemangiomas. Also lymphangiomas may be apparent.

Patients are normal at birth and the syndrome manifests during childhood and puberty. The enchondromas affect the extremities and their distribution is asymmetrical.

Genetic changes are related to the following types of collagenopathy, types II and XI.

The system for classifying collagenopathies is changing as researchers learn more about the genetic causes of these disorders.The clinical features of the type II and XI collagenopathies vary among the disorders, but there is considerable overlap. Common signs and symptoms include problems with bone development that can result in short stature, enlarged joints, spinal curvature, and arthritis at a young age. For some people, bone changes can be seen only on X-ray images. Problems with vision and hearing, as well as a cleft palate with a small lower jaw, are common. Some individuals with these disorders have distinctive facial features such as protruding eyes and a flat nasal bridge.

"Fibrous dysplasia" causes bone thinning and growths or lesions in one or more bones of the human body.

These lesions are tumor-like growths that consist of replacement of the medullary bone with fibrous tissue, causing the expansion and weakening of the areas of bone involved. Especially when involving the skull or facial bones, the lesions can cause externally visible deformities. The skull is often, but not necessarily, affected, and any other bone(s) can be involved.

Signs vary widely based on which type of EDS the patient has. In each case, however, the signs are ultimately due to faulty or reduced amounts of collagen. EDS typically affects the joints, skin, and blood vessels. Following is a list of major signs and symptoms.

Infants born with this condition have very short arms and legs, a narrow chest, and a prominent, rounded abdomen. This disorder is also characterized by an opening in the roof of the mouth (cleft palate), distinctive facial features, an inward- and downward-turning foot (clubfoot), and unusually positioned thumbs (hitchhiker thumbs).

The signs and symptoms of atelosteogenesis, type 2, are similar to those of another skeletal disorder called diastrophic dysplasia. Atelosteogenesis, type 2 tends to be more severe, however.

Because it is often undiagnosed or misdiagnosed in childhood, some instances of Ehlers–Danlos syndrome have been mischaracterized as child abuse.

The pain associated with the condition may be severe.

People with this condition are short-statured from birth, with a very short trunk and shortened limbs. Their hands and feet, however, are usually average-sized. Curvature of the spine (scoliosis and lumbar lordosis) may be severe and can cause problems with breathing. Changes in the spinal bones (vertebrae) in the neck may also increase the risk of spinal cord damage. Other skeletal signs include flattened vertebrae (platyspondyly), severe protrusion of the breastbone (pectus carinatum), a hip joint deformity in which the upper leg bones turn inward (coxa vara), and a foot deformity known as clubfoot.

Affected individuals have mild and variable changes in their facial features. The cheekbones close to the nose may appear flattened. Some infants are born with an opening in the roof of the mouth, which is called a cleft palate. Severe nearsightedness (high myopia) and detachment of the retina (the part of the eye that detects light and color) are also common.

Spondyloperipheral dysplasia is an autosomal dominant disorder of bone growth. The condition is characterized by flattened bones of the spine (platyspondyly) and unusually short fingers and toes (brachydactyly). Some affected individuals also have other skeletal abnormalities, short stature, nearsightedness (myopia), hearing loss, and mental retardation. Spondyloperipheral dysplasia is a subtype of collagenopathy, types II and XI.

The distinctive characteristics of OSMED include severe bone and joint problems and very severe hearing loss. This disorder affects the epiphyses, the parts of the bone where growth occurs. People with the condition are often shorter than average because the bones in their arms and legs are unusually short. Other skeletal signs include enlarged joints, short hands and fingers, and flat bones of the spine (vertebrae). People with the disorder often experience back and joint pain, limited joint movement, and arthritis that begins early in life. Severe high-tone hearing loss is common. Typical facial features include protruding eyes; a sunken nasal bridge; an upturned nose with a large, rounded tip; and a small lower jaw. Some affected infants are born with an opening in the roof of the mouth, which is called a cleft palate.

People with spondyloepiphyseal dysplasia are short-statured from birth, with a very short trunk and neck and shortened limbs. Their hands and feet, however, are usually average-sized. This type of dwarfism is characterized by a normal spinal column length relative to the femur bone. Adult height ranges from 0.9 meters (35 inches) to just over 1.4 meters (55 inches). Curvature of the spine (kyphoscoliosis and lordosis) progresses during childhood and can cause problems with breathing. Changes in the spinal bones (vertebrae) in the neck may also increase the risk of spinal cord damage. Other skeletal signs include flattened vertebrae (platyspondyly), a hip joint deformity in which the upper leg bones turn inward (coxa vara), and an inward- and downward-turning foot (called clubfoot). Decreased joint mobility and arthritis often develop early in life. Medical texts often state a mild and variable change to facial features, including cheekbones close to the nose appearing flattened, although this appears to be unfounded. Some infants are born with an opening in the roof of the mouth, which is called a cleft palate. Severe nearsightedness (high myopia) is sometimes present, as are other eye problems that can affect vision such as detached retinas. About one-quarter of people with this condition have mild to moderate hearing loss.

Gerodermia osteodysplastica is characterized by symptoms and features which affect the connective tissues, skin and skeletal system.

These are: wrinkly, loose skin over the face, abdomen, and extremites (hands, feet) on the dorsal sides usually worsened by chronic joint laxity and hyperextensibility; fragmented elastic fibers of the skin that are reduced in number, with disorientation of collagen fibers; osteopenia and osteoporosis, with associated fractures; malar hypoplasia (underdeveloped cheek bone), maxillary hypoplasia (underdeveloped upper jaw), mandibular prognathism (protrusion of the lower jaw and chin), bowed long bones, platyspondyly (flattened spine) related to vertebral collapse; kyphoscoliosis (scoliosis with kyphosis, or "hunch back"), metaphyseal peg (an unusual outgrowth of metaphyseal tissue which protrudes into the epiphyseal region of the bone, near the knee); and the overall physical effects and facial appearance of dwarfism with premature aging.

Other features and findings include: intrauterine growth retardation, congenital hip dislocations, winged scapulae (shoulder blades), pes planus (fallen arches), pseudoepiphyses of the second metacarpals (upper bone of the fingers), hypotelorism (close-set eyes), malformed ears,

developmental delay,

failure to thrive and abnormal electroencephalograph (EEG) readings.

Dental and orthodontal abnormalities in addition to maxillary hypoplasia and mandibular prognathism have also been observed in gerodermia osteodysplastica. Including malocclusion of the dental arches (the maxilla and mandible), radiological findings in some cases have indicated significant overgrowth of the mandibular premolar and molar roots;

hypercementosis (overproduction of cementum) of the molars and maxillary incisors; enlarged, funnel-shaped mandibular lingula (spiny structures on the ramus of the mandible); and a radiolucent effect on portions of many teeth, increasing their transparency to x-rays.

Because collagen plays an important role in the development of the body, people with Kniest Dysplasia will typically have their first symptoms at birth. These symptoms can include:.

- Musculoskeletal Problems

- Short limbs

- Shortened body trunk

- Flattened bones in the spine

- kyphoscoliosis

- Scoliosis (Lateral curvature of the spine)

- Early development of arthritis

- Respiratory problems

- Respiratory tract infection

- Difficulty breathing

- Eye problems

- Severe myopia (near-sightedness)

- Cataract (cloudiness in the lens of the eye)

- Hearing problems

- progressive hearing loss

- ear infections

Most symptoms are chronic and will continue to worsen as the individual ages. It is essential to have regular checkups with general doctors, orthopedist, ophthalmologists, and/or otorhinolaryngologists. This will help to detect whether there are any changes that could cause concern.

Children with autosomal dominant MED experience joint pain and fatigue after exercising. Their x-rays show small and irregular ossifications centers, most apparent in the hips and knees. A waddling gait may develop. Flat feet are very common.

The spine is normal but may have a few irregularities, such as scoliosis. There are very small capital femoral epiphyses and hypoplastic, poorly formed acetabular roofs. Knees have metaphyseal widening and irregularity while hands have brachydactyly (short fingers) and proximal metacarpal rounding. By adulthood, people with MED are of short stature or in the low range of normal and have short limbs relative to their trunks. Frequently, movement becomes limited at the major joints, especially at the elbows and hips. However, loose knee and finger joints can occur. Signs of osteoarthritis usually begin in early adulthood.

Children with recessive MED experience joint pain, particularly of the hips and knees, and commonly have deformities of the hands, feet, knees, or vertebral column (like scoliosis). Approximately 50% of affected children have abnormal findings at birth (such as club foot or twisted metatarsals, cleft palate, inward curving fingers due to underdeveloped bones and brachydactyly, or ear swelling caused by injury during birth). Height is in the normal range before puberty. As adults, people with recessive MED are only slightly more diminished in stature, but within the normal range. Lateral knee radiography can show multi-layered patellae.

Patients with CED complain of chronic bone pain in the legs or arms, muscle weakness (myopathy) and experience a waddling gait. Other clinical problems associated with the disease include increased fatigue, weakness, muscle spasms, headache, difficulty gaining weight, and delay in puberty. Some patients have an abnormal or absent tibia, may present with a flat foot, or scoliosis.

This disease may also cause bones to become abnormally hardened which is referred to as sclerosis. This hardening may affect the bones at the base of the skull or those in the hands, feet, or jaw. This causes ongoing pain and aching within the body parts that are affected. The pain has been described as either a hot electric stabbing pain, an ever-increasing pressure sensation around the bones (especially before electrical storms) or as a constant ache that radiates through several long bones at once. Pain may also occur in the hips, wrists, knees and other joints as they essentially just 'lock-up' (often becoming very stiff, immobile and sore), mostly when walking up or down staircases, writing for extended periods of time, or during the colder months of the year. Those with the disease tend to have a very characteristic walk medically diagnosed as a 'waddling gait'. This is observed by the broad-based gait with a duck-like waddle to the swing phase, the pelvis drops to the side of the leg being raised, notable forward curvature of the lumbar spine and a marked body swing.

The pain is especially severe during a 'flare-up', these can be unpredictable, exhausting and last anywhere from a few hours to several weeks. This is a common occurrence for several CED patients, often causing myopathy and extensive sleep deprivation from the chronic, severe and disabling pain. Patients may even require the use of a wheelchair (or additional carer's help with getting dressed, showering, mobility/shopping, preparing meals or lifting heavy items) especially when bedridden or housebound for days or weeks at a time. 'Flare-ups' may be attributed to, or exacerbated by growth spurts, stress, exhaustion, exercise, standing or walking for too long, illness, infection, being accidentally knocked/hurt or injured, after surgery/anaesthetics, cold weather, electrical storms, and sudden changes in barometric pressure.

CED may also affect internal organs, the liver and spleen, which may become enlarged. A loss of vision and/or hearing can occur if bones are adversely affected by the hardening in the skull. Hence proactive specialist check-ups, X-rays, diagnostic tests/scans, and regular blood tests are recommended on an annual basis to monitor the CED bony growth and secondary medical issues that may arise from this condition.

The type II and XI collagenopathies are a group of disorders that affect connective tissue, the tissue that supports the body's joints and organs. These disorders are caused by defects in type II or type XI collagen. Collagens are complex molecules that provide structure, strength, and elasticity to connective tissue. Type II and type XI collagen disorders are grouped together because both types of collagen are components of the cartilage found in joints and the spinal column, the inner ear, and the jelly-like substance that fills the eyeball (the vitreous). The type II and XI collagenopathies result in similar clinical features.

Atelosteogenesis, type II is a severe disorder of cartilage and bone development. It is rare, and infants with the disorder are usually stillborn; however, those who survive birth die soon after

Bruck syndrome is characterized as the combination of arthrogryposis multiplex congenita and osteogenesis imperfecta. Both diseases are uncommon, but concurrence is extremely rare which makes Bruck syndrome very difficult to research. Bruck syndrome is thought to be an atypical variant of osteogenesis imperfecta most resembling type III, if not its own disease. Multiple gene mutations associated with osteogenesis imperfecta are not seen in Bruck syndrome. Many affected individuals are within the same family, and pedigree data supports that the disease is acquired through autosomal recessive inheritance. Bruck syndrome has features of congenital contractures, bone fragility, recurring bone fractures, flexion joint and limb deformities, pterygia, short body height, and progressive kyphoscoliosis. Individuals encounter restricted mobility and pulmonary function. A reduction in bone mineral content and larger hydroxyapatite crystals are also detectable Joint contractures are primarily bilateral and symmetrical, and most prone to ankles. Bruck syndrome has no effect on intelligence, vision, or hearing.

Spondyloepimetaphyseal dysplasia, Strudwick type is an inherited disorder of bone growth that results in dwarfism, characteristic skeletal abnormalities, and problems with vision. The name of the condition indicates that it affects the bones of the spine (spondylo-) and two regions near the ends of bones (epiphyses and metaphyses). This type was named after the first reported patient with the disorder. Spondyloepimetaphyseal dysplasia, Strudwick type is a subtype of collagenopathy, types II and XI.

The signs and symptoms of this condition at birth are very similar to those of spondyloepiphyseal dysplasia congenita, a related skeletal disorder. Beginning in childhood, the two conditions can be distinguished in X-ray images by changes in areas near the ends of bones (metaphyses). These changes are characteristic of spondyloepimetaphyseal dysplasia, Strudwick type.

Opsismodysplasia can be characterized by a delay in bone maturation, which refers to "bone aging", an expected sequence of developmental changes in the skeleton corresponding to the chronological age of a person. Factors such as gender and ethnicity also play a role in bone age assessment. The only indicator of physical development that can be applied from birth through mature adulthood is bone age. Specifically, the age and maturity of bone can be determined by its state of ossification, the age-related process whereby certain cartilaginous and soft tissue structures are transformed into bone. The condition of epiphyseal plates (growth plates) at the ends of the long bones (which includes those of the arms, hands, legs and feet) is another measurement of bone age. The evaluation of both ossification and the state of growth plates in children is often reached through radiography (X-rays) of the carpals (bones of the hand and wrist). In opsismodysplasia, the process of ossification in long bones can be disrupted by a failure of ossification centers (a center of organization in long bones, where cartilage cells designated to await and undergo ossification gather and align in rows) to form. This was observed in a 16-month-old boy with the disorder, who had no apparent ossification centers in the carpals (bones of the hand and wrist) or tarsals (bones of the foot). This was associated with an absence of ossification in these bones, as well as disfigurement of the hands and feet at age two. The boy also had no ossification occurring in the lower femur (thigh bone) and upper tibia (the shin bone).

Diagnosis is mostly based on general examination and radiographs, and it should be taken when abnormality of the teeth is suspected as most of the affected teeth have normal clinical appearance.

Differential diagnosis is very important to have a definitive diagnosis as some radiographic or histologic features of dentine dysplasia may bear a resemblance to different disorders:

- Dentinogenesis Imperfecta

- Odontodysplasia

- Calcinosis

- Osteogenesis imperfecta

- Ehlers Danlos syndrome

- Goldblatt syndrome

- Schimke immuno-osseous dysplasia

- Brachio-skeleto-genital syndrome.

Disproportionate short stature, deformity of the lower limbs, short fingers, and

ligamentous laxity give pseudoachondroplasia its distinctive features. The average height of adult males with the condition is around 120 centimeters (3 ft, 11 in), while adult females are typically around 116 cm (3ft, 9in). Affected individuals are not noticeably short at birth. Patients with pseudoachondroplasia present with gait abnormalities, lower limb deformity, or a retarded growth rate that characteristically appear at age 2-3 years. Disproportionate short stature is characterized by shortening of proximal limb segments (humeri and femora) also called rhizomelic shortening. Other known clinical features include, genu valgum/varum, brachydactyly (short fingers), supple flexion deformity of the hips, knees, hyperlordosis of lumbar spine, rocker bottom feet and broadening of the metaphyseal ends of long bones especially around the wrists, knees and ankles. Patients with pseudoachondroplasia have normal intelligence and craniofacial features, “Figure 1”, “Figure 2”, “Figure 3”.

Spondyloepiphyseal dysplasia congenita (abbreviated to SED more often than SDC) is a rare disorder of bone growth that results in dwarfism, characteristic skeletal abnormalities, and occasionally problems with vision and hearing. The name of the condition indicates that it affects the bones of the spine (spondylo-) and the ends of bones (epiphyses), and that it is present from birth (congenital). The signs and symptoms of spondyloepiphyseal dysplasia congenita are similar to, but milder than, the related skeletal disorders achondrogenesis type 2 and hypochondrogenesis. Spondyloepiphyseal dysplasia congenita is a subtype of collagenopathy, types II and XI.

Dentin dysplasia (DD) is a rare genetic developmental disorder dentine production of the teeth, commonly exhibiting an autosomal dominant inheritance that causes malformation of the root. It affects both primary and permanent dentitions in approximately 1 in every 100,000 patients. It is characterized by presence of normal enamel but atypical dentin with abnormal pulpal morphology. Witkop in 1972 classified DD into two types which are Type I (DD-1) is the radicular type, and type II (DD-2) is the coronal type. DD-1 has been further divided into 4 different subtypes (DD-1a,1b,1c,1d) based on the radiographic features.