Types of Osteochondrodysplastic Dwarfism

Achondroplasia

Bulky forehead, saddle nose, lumbar lordosis, bowlegs

AD

Fibroblast growth factor receptor 3 (FGFR)

Chondrodysplasia punctata

Variable extraskeletal manifestations

X-rays show epiphyseal stippling in infancy due to calcifications

See below

See below

Chondrodysplasia punctata (rhizomelic form)

Marked proximal limb shortening

Death during infancy

AR

Peroxisomal type 2 targeting signal receptor (PTS2)

Chondrodysplasia punctata (Conradi-Hünermann form)

Mild, asymmetric limb shortening

Benign

AD or XL dominant

Delta(8)-delta(7)-sterol isomerase emopamil-binding protein (EBP)

Chondroectodermal dysplasia (Ellis-van Creveld [EVC] syndrome)

Distal limb shortening, postaxial polydactyly, structural cardiac defects

AR

EVC, EVC2

Diastrophic dysplasia

Severe dwarfism with rigid hitchhiker thumb and fixed talipes equinovarum

AR

Solute carrier family 26 (sulfate transporter), member 2 (SLC26A2)

Hypochondroplasia

Symptoms of achondroplasia but milder

AD

Fibroblast growth factor receptor 3 (FGFR3—not all patients)

Mesomelic dysplasia* (Langer type)

Predominantly, shortening of the forearms and shanks

Normal facies and spine

AR

Short stature homeobox (SHOX), short stature homeobox Y-linked (SHOXY)

Metaphyseal chondrodysplasia†

In some forms, malabsorption, neutropenia, thymolymphopenia

AR or AD

Multiple epiphyseal dysplasia

Mild dwarfism, normal spine and facies, sometimes stubby digits, hip dysplasia (often as 1st symptom)

Very heterogeneous

AR or AD

Solute carrier family 26 (sulfate transporter), member 2 (SLC26A2; AR form)

Pseudoachondroplasia

Normal facies, various degrees of dwarfism and kyphoscoliosis

Heterogeneous

AD or AR

Cartilage oligomeric matrix protein (COMP)

Spondyloepiphyseal dysplasia

Predominantly, kyphoscoliosis

Sometimes myopia and a flat facies

Heterogeneous

AD, AR, or XL recessive

Type II collagen (COL2A1), tracking protein particle complex, subunit 2 (TRAPPC2, also known as SEDL)