In classic non-deforming osteogenesis imperfecta with blue sclerae or common variable osteogenesis imperfecta with normal sclerae, nearly 60% of cases are de novo. COL1A1/2-related osteogenesis imperfecta is identified by repeated fractures with trivial trauma, defective dentinogenesis imperfecta (DI), and hearing loss. The clinical features of COL1A1/2-related osteogenesis imperfecta can be highly variable ranging from severe and lethal perinatal fractures to individuals with minimal tendency to repeated fractures and skeletal deformities and with a normal stature and life span. In between the clinical spectrum may include individuals with various degrees of disabling skeletal deformities and short stature. The radiographic findings of osteogenesis imperfecta include; long bone deformations such as bowing of the tibias and femurs, pencil-like deformity and tapering of bones, cortical thinning and rarefaction, pathologic fractures at various degrees of healing, bone shortening and vertebral wedging. Accordingly, COL1A1/2-related osteogenesis imperfecta has been classified into four sub-types (I, II, III, and IV) built upon the diversity of the radioclinical features. OI type I: classic non-deforming OI with blue sclerae
OI type II: perinatally lethal OI
OI type III: progressively deforming OI
OI type IV: common variable OI with normal sclerae

Muocopolysachariodosis
Mucopolysaccharidoses (MPS) constitute a commonly seen group of osteochondrodysplasias. Mucopolysaccharidosis can cause a wide spectrum of clinical and radiologic manifestations ranging from mild skeletal and systemic involvement to severe life-threatening manifestations. It is caused by a contiguous gene duplication or deletion syndrome in which multiple genes are involved. All forms of MPS are inherited in an autosomal recessive pattern, except fir of MPS II; Hunter syndrome which is X-linked.
The features associated with this condition include mild to moderate learning difficulties, short stature, unique facial features, small head and skeletal abnormalities including bony growths projecting from the surfaces of bones. Maffucci syndrome
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. Osteosclerosis
Osteosclerosis, an elevation in bone density, is normally detected on an X-ray as an area of whiteness, and is where the bone density has significantly increased. Localized osteosclerosis can be caused by injuries that compress the bone, by osteoarthritis, and osteoma. Other
Deformity type Erlenmeyer flask gives a distal femur similar to an Erlenmeyer flask. It may result from Gaucher disease. Kashin–Beck disease
Melnick–Needles syndrome
Ovine chondrodysplasia
Familial osteodysplasia, Anderson type

Diagnosis
The diagnosis is mainly based upon delineating the specific clinical and radiographic pattern of skeletal involvement. However, the different types of skeletal dysplasia can overlap considerably in their clinical presentation. Molecular or genetic analysis may be required to resolve diagnostic difficulties. Molecular analysis is also of importance to the phenotype genotype correlations and to disease classifications. Differential diagnosis
Juvenile idiopathic arthritis may closely resemble the clinical presentation of some osteochondrodysplasias or genetic skeletal dysplsias. In that, both conditions can present with swollen, stiff and deformed joints. Treatment
Emerging therapies for genetic skeletal dysplasias include  enzyme replacement therapy,  hematopoietic stem cell transplantation and  gene therapy.