Osteopetrosis may be inherited as either a dominant or recessive trait and is marked by increased bone density, brittle bones, and, in some cases, skeletal abnormalities. Although symptoms may not initially be apparent in people with mild forms of...

Apert syndrome, also known as acrocephalosyndactyly type I (ACS1), is a rare genetic disorder that is apparent at birth (congenital). The disorder is character-ized by distinctive malformations of the head that lead to distinctive facial features....

Baller-Gerold Syndrome is a rare genetic disorder that is apparent at birth (congenital). The disorder is characterized by distinctive malformations of the skull and facial (craniofacial) area and bones of the forearms and hands. In in...

Osteogenesis Imperfecta (OI) is a group of rare disorders affecting the connective tissue and characterized by extremely fragile bones that break or fracture easily (brittle bones), often without apparent cause. The specific symptoms and physical ...

Osteogenesis Imperfecta (OI) is a group of rare disorders affecting the connective tissue and characterized by extremely fragile bones that break or fracture easily (brittle bones), often without apparent cause. The specific symptoms and physical ...

Campomelic syndrome is a rare congenital disorder in which multiple anomalies are present. It is characterized by bowing and angular shape of the long bones of the legs, especially the tibia; multiple minor anomalies of the face; cleft palate; oth...

Campomelic syndrome is a rare congenital disorder in which multiple anomalies are present. It is characterized by bowing and angular shape of the long bones of the legs, especially the tibia; multiple minor anomalies of the face; cleft palate; oth...

Camptomelic syndrome is a rare congenital disorder in which multiple anomalies are present. It is characterized by bowing and angular shape of the long bones of the legs, especially the tibia; multiple minor anomalies of the face; cleft palate; ot...

Camptomelic syndrome is a rare congenital disorder in which multiple anomalies are present. It is characterized by bowing and angular shape of the long bones of the legs, especially the tibia; multiple minor anomalies of the face; cleft palate; ot...

Camptomelic syndrome is a rare congenital disorder in which multiple anomalies are present. It is characterized by bowing and angular shape of the long bones of the legs, especially the tibia; multiple minor anomalies of the face; cleft palate; ot...

Cutis laxa is rarely encountered and may occur in several inherited (congenital) forms or come about in the course of another disorder (acquired). It is a connective tissue disorder characterized by skin that is loose (lax), hanging, wrinkled, and...

De Barsy syndrome is a rare, autosomal recessive genetic disorder, the main characteristics of which are a prematurely aged-looking face (progeria), cloudy corneas, short stature, and mental retardation. The condition is expressed in variable pres...

Microvillus inclusion disease is an extremely rare inherited intestinal disorder (enteropathy) that is typically apparent within hours or days after birth. The disorder is characterized by chronic, severe, watery diarrhea and insufficient absorpti...

De Barsy syndrome is a rare, autosomal recessive genetic disorder, the main characteristics of which are a prematurely aged-looking face (progeria), cloudy corneas, short stature, and mental retardation. The condition is expressed in variable pres...

Dyschondrosteosis is a very rare inherited disorder characterized by unusually shortened, bowed bones in the forearms (radius and ulna), abnormal deviation of the wrist toward the thumb side of the hand due to shortening of the radius and dislocat...

Ollier disease is a rare skeletal disorder characterized by abnormal bone development (skeletal dysplasia). While this disorder may be present at birth (congenital); it may not become apparent until early childhood when symptoms, such as deformiti...

Epidermal nevus syndromes (ENSs) are a group of rare complex disorders characterized by the presence of skin lesions known as epidermal nevi associated with additional extra-cutaneous abnormalities, most often affecting the brain, eye and skeletal...

Oculo-auriculo-vertebral spectrum (OAVS) refers to three rare disorders that many clinicians believe to be intimately related to one another and which represent the range of severity of the same disorder. These disorders are apparent at birth (con...

Langerhans cell histiocytosis (LCH) is a spectrum of rare disorders characterized by overproduction (proliferation) and accumulation of a specific type of white blood cell (histiocyte) in the various tissues and organs of the body (lesions). The l...

Hypercalcemia Introduction Calcium is a mineral that is important in the regulation and processes of many body functions including bone formation, hormone release, muscle contraction, and nerve and brain function. Hypercalcemia is the term...

wJansen type metaphyseal chondrodysplasia is an extremely rare progressive disorder in which portions of the bones of the arms and legs develop abnormally with unusual cartilage formations and subsequent abnormal bone formation at the large (bulbo...

Jansen type metaphyseal chondrodysplasia is an extremely rare progressive disorder in which portions of the bones of the arms and legs develop abnormally with unusual cartilage formations and subsequent abnormal bone formation at the large (bulbou...

Jarcho-Levin syndrome is a rare genetic disorder characterized by distinctive malformations of bones of the spinal column (vertebrae) and the ribs, respiratory insufficiency, and/or other abnormalities. Infants born with Jarcho-Levin syndrome have...

A keloid scar forms from abnormal healing, and usually develops in people 10 to 20 years old. A keloid, or keloid scar, is a kind of overgrown scar, or an overly aggressive healing response to a wound. It's a type of thick, irregul...

Kohler disease is a rare bone disorder of the foot in children that may be the result of stress-related compression at a critical time during the period of growth. It is characterized by limping caused by pain and swelling in the foot. It most oft...

Kohler disease is a rare bone disorder of the foot in children that may be the result of stress-related compression at a critical time during the period of growth. It is characterized by limping caused by pain and swelling in the foot. It most oft...

Osteopetrosis may be inherited as either a dominant or recessive trait and is marked by increased bone density, brittle bones, and, in some cases, skeletal abnormalities. Although symptoms may not initially be apparent in people with mild forms of...

Marfan syndrome is a genetic disorder that affects connective tissue, which is the material between cells of the body that gives the tissues form and strength. Connective tissue is found all over the body and multiple organ systems may be affected...

Antley-Bixler Syndrome is a rare genetic disorder that is primarily characterized by distinctive malformations of the head and facial (craniofacial) area and additional skeletal abnormalities. For example, the disorder is typically associated with...

Ollier disease is a rare skeletal disorder characterized by abnormal bone development (skeletal dysplasia). While this disorder may be present at birth (congenital); it may not become apparent until early childhood when symptoms, such as deformiti...

Nail-patella syndrome (NPS) is a rare genetic disorder that is usually apparent at birth or during early childhood. Although the symptoms and physical characteristics associated with NPS may vary, characteristic abnormalities tend to include impro...

Familial hypophosphatemia is a rare inherited disorder characterized by impaired transport of phosphate and often altered vitamin-D metabolism in the kidneys. In addition, phosphate may not be well-absorbed in the intestines. The hypophosphatemia ...

5-Oxoprolinuria is a biochemical finding that can arise from two underlying metabolic disorders. It is characterized by excretion of massive amounts of the chemical 5-oxoproline....

A rheumatic disease affects the joints and connective tissues. Arthritis, gout, and ankylosing spondylitis are just three of the more than 100 types of rheumatic diseases. More than 100 diseases are classified as rheumatic diseases, includ...

Phocomelia syndrome (PS) is a rare birth defect that causes severe birth defects, especially of the upper limbs. The bones of the arms, and in some cases other appendages, may be extremely shortened and even absent. The fingers of the hands may be...

Parry-Romberg syndrome is a rare, acquired disorder characterized by slowly progressive shrinkage (atrophy) of the skin and soft tissues of half of the face (hemifacial atrophy). In rare cases, both sides of the face are affected. In some cases, a...

Rothmund-Thomson syndrome (RTS) is a rare genetic disorder that can affect many parts of the body. The disorder is characterized by distinctive abnormalities of the skin, sparse hair, eyelashes and/or eyebrows, small stature, skeletal and dental a...

Rothmund-Thomson syndrome is a rare condition that affects many parts of the body, particularly the skin....

Weismann-Netter-Stuhl syndrome is an extremely rare genetic skeletal disorder characterized by the abnormal development of bone (osseousbo dysplasia). Affected individuals exhibit bowing of the long portions (shafts) of the shinbone (tibia) and th...

Apert syndrome, also known as acrocephalosyndactyly type I (ACS1), is a rare genetic disorder that is apparent at birth (congenital). The disorder is characterized by distinctive malformations of the head that lead to distinctive facial features. ...

Tricho-dento-osseous (TDO) syndrome is an autosomal dominant genetic disorder that belongs to a group of diseases known as ectodermal dysplasias. Ectodermal dysplasias typically affect the hair, teeth, nails, and/or skin. TDO syndrome is character...

Antley-Bixler Syndrome is a rare genetic disorder that is primarily characterized by distinctive malformations of the head and facial (craniofacial) area and additional skeletal abnormalities. For example, the disorder is typically associated with...

What is vitamin D? The "sunshine" vitamin is a hot topic. You may have recently found out that you are deficient or know someone who is. It's shocking for most people when they have never had a problem before and believe nothing has change...

Osteogenesis Imperfecta (OI) is a group of rare disorders affecting the connective tissue and characterized by extremely fragile bones that break or fracture easily (brittle bones), often without apparent cause. The specific symptoms and physical ...

General DiscussionRomano-Ward syndrome is an inherited heart (cardiac) disorder characterized by abnormalities affecting the electrical system of the heart. The severity of Romano-Ward syndrome varies greatly from case to case. Some indiv...

Weismann-Netter-Stuhl syndrome is an extremely rare inherited skeletal disorder characterized by the abnormal development of bone (osseous dysplasia). Affected individuals exhibit bowing of the long portions (shafts) of the shinbone (tibia) and th...

Wieacker syndrome is a rare, slowly progressive, genetic disorder characterized by deformities of the joints of the feet (contracture), muscle degeneration (atrophy), mild mental retardation and an impaired ability to move certain muscles of the e...

Wildervanck syndrome, also known as cervicooculoacoustic syndrome, is a rare genetic disorder that primarily affects females. The disorder is characterized by a skeletal condition known as Klippel-Feil syndrome (KFS); abnormalities of certain eye ...

Familial hypophosphatemia is a rare inherited disorder characterized by impaired transport of phosphate and often altered vitamin-D metabolism in the kidneys. In addition, phosphate may not be well-absorbed in the intestines. The hypophosphatemia ...