Table 2

Summary of the key clinical manifestations, onset, severity, treatment, prognosis and recurrence risks of the main types of osteopetrosis

Osteopetrosis subtype
Autosomal recessive osteopetrosis (ARO)
X-linked osteopetrosis, lymphedema, anhidrotic ectodermal dysplasia and immunodeficiency (OLEDAID)
Intermediate osteopetrosis (IRO)
Autosomal dominant osteopetrosis
(Albers-Schönberg
disease)






Classic
Neuropathic
ARO with RTA




Genetic basis
TCIRG
CLCN7, OSTM1
Carbonic anhydrase II
IKBKG (NEMO)
CLCN7, PLEKHM1
CLCN7

Skeletal manifestations

Increased bone density, diffuse and focal sclerosis of varying severity
Modelling defects at metaphyses
Pathological fractures
Osteomyelitis
Dental abnormalities: tooth eruption defects and dental caries





Other manifestations
Pancytopaenia.
Extramedullary haematopoiesis, hepatosplenomegaly.
Cranial nerve compression (II, VII, VIII)
Hydrocephalus
Hypocalcaemia
As for classic ARO, but primary neurodegeneration, including retinal atrophy
Renal tubular acidosis.
Developmental delay. Intracranial calcification.
Cranial nerve compression.
Bone marrow impairment rare.
Anhidrotic ectodermal dysplasia.
Lymphedema.
Immunodeficiency resulting in overwhelming infection.
Anaemia and extramedullary haematopoiesis
Occasional optic nerve compression
Moderate haematological failure
Cranial nerve compression

Onset
Perinatal
Perinatal
Infancy
Infancy
Childhood
Late childhood or adolescence

Severity
Severe
Severe
Moderate
Severe
Mild to moderate
Mild to moderate, occasionally severe

Treatment
Supportive
HSCT
Supportive
Supportive
May benefit from HSCT
Supportive
Supportive
Supportive

Prognosis
Poor
Fatal in infancy
Poor
Fatal in infancy
Variable
Poor
Fatal in early childhood
Variable
Normal life expectancy

Recurrence risk
Parents of proband: 25% risk of recurrence in future pregnancies


If mother of proband carrier: 50% of male pregnancies affected
Parents of proband: 25% risk of recurrence in future pregnancies
50% in future pregnancies if one parent affected

Stark and Savarirayan Orphanet Journal of Rare Diseases 2009 4:5   doi:10.1186/1750-1172-4-5