"The underlying genetic abnormality is almost exclusively due to a mutation in the ALPL gene that encodes for tissue non-specific alkaline phosphatase (TNSAP) enzyme. This results in defective bone mineralisation and extracellular accumulation of TNSAP substrates. With over 300 different specific mutations recognised, the severity of the resultant clinical disorder depends on the degree to which TNSAP activity is impaired. The severer the impairment, the earlier the presentation."
"Looser zones 6"
Expected headings
"Subtypes"
"Skeletal manifestations"