Achondrogenesis (Type-2)

Definition

Definition of Achondrogenesis (Type-2)
Infants with achondrogenesis, type 2 have short arms and legs, a small chest with short ribs, and underdeveloped lungs. Achondrogenesis, type 2 is a subtype of collagenopathy, types II and XI. This condition is also associated with a lack of bone formation (ossification) in the spine and pelvis. Typical facial features include a prominent forehead, a small chin, and, in some cases, an opening in the roof of the mouth (a cleft palate). The abdomen is enlarged, and affected infants often have a condition called hydrops fetalis in which excess fluid builds up in the body before birth. The skull bones may be soft, but they often appear normal on X-ray images. In contrast, bones in the spine (vertebrae) and pelvis do not harden.

Achondrogenesis, type 2 and hypochondrogenesis (a similar skeletal disorder) together affect 1 in 40,000 to 60,000 births. Achondrogenesis, type 2 is one of several skeletal disorders caused by mutations in the COL2A1 gene. This gene provides instructions for making a protein that forms type II collagen. This type of collagen is found mostly in cartilage and in the clear gel that fills the eyeball (the vitreous). It is essential for the normal development of bones and other tissues that form the body's supportive framework (connective tissues). Mutations in the COL2A1 gene interfere with the assembly of type II collagen molecules, which prevents bones and other connective tissues from developing properly.

Symptoms

Symptoms of Achondrogenesis (Type-2)
The list of signs and symptoms for Achondrogenesis type 2 includes the 31 symptoms listed below:

1. Low birth weight
2. Small birth size
3. Extremely short stature
4. Large calvarium
5. Large head
6. Large prominent forehead
7. Flat face
8. Short neck
9. Short flared chest
10. Protruding abdomen in infants
11. Large anterior fontanels
12. Large posterior fontanels
13. Flat nose bridge
14. Small nostrils
15. Anteverted nostrils
16. Small lower jaw
17. Short limbs
18. Short ribs
19. Short long bones
20. Broad long bones
21. Long fibula
22. Metaphyseal irregularity of distal ulna
23. Ossification failure of lumbar spine
24. Ossification failure of neck bones
25. Ossification failure of sarcum
26. Ossification failure of ischial bones
27. Ossification failure of pubic bones
28. Ossification failure of cancaneus
29. Ossification failure of talus
30. Excessive amniotic fluid
31. Shortened life span - death occurs before the end of the second decade

Causes

Causes of Achondrogenesis (Type-2)
Achondrogenesis type 2 is caused by mutations in the COL2A1 gene, which is involved in converting cartilage to bone.

Tests

Tests of Achondrogenesis (Type-2)
These home medical tests may be relevant to Achondrogenesis type 2:
o ADHD -- Home Test Kits
o Concentration -- Home Testing

Prognosis

Prognosis of Achondrogenesis (Type-2)
Death is common before or soon after birth but some may survive into their early teens.

Treatment

Treatment of Achondrogenesis (Type-2)
Always seek professional medical advice about any treatment or change in treatment plans. There is no treatment for the underlying cause. Genetic counseling and joining a support group is usually recommended.

Complications

Complications of Achondrogenesis (Type-2)
Complications of Achondrogenesis type 2 may include:

1. Stillbirth
2. Breech birth
3. Hydrops
4. Death - within hours of birth due to underdeveloped lungs