Houston-Harris sub type

Achondrogenesis type Ia, also known as the Houston-Harris subtype, is a subtype of achondrogenesis. It is an extremely rare lethal skeletal dysplasia (chondrodysplasia) with a characteristic severe disarrangement of endochondral ossification.

Clinical presentation

Some of the common clinical features include:

• low birth weight
• skeletal abnormalities
• very short limbs
• short neck
• incomplete ossification of bones - particularly the skull
• congenital cardiac anomalies
  • patent ductus arteriosus
  • atrial septal defects
  • ventricular septal defects
• breathing problems
• small chest
• underdeveloped lungs
• protuberant abdomen

Pathology

The growth plate cartilage completely lacks columnar-zone formation and shows chondrocyte expansion due to intracellular vacuoles.

See also

• achondrogenesis
  • type I: 
    • type Ia: Houston-Harris subtype
    • type Ib: Parenti-Fraccaro subtype
  • type II: Langer-Saldino syndrome