Hypophosphatasia (Subscribe)  

Upon completion of this activity, participants will be able to:
Describe the typical presentation and management of Hypophosphatasia, a rarely encountered medical condition in clinical practice

Review of genetic abnormalities of Alkaline Phosphatase in bone, liver and kidney. 16 different types noted.

#146300 HYPOPHOSPHATASIA, ADULT TYPE Alternative titles; symbols HYPOPHOSPHATASIA, MILD ODONTOHYPOPHOSPHATASIA, INCLUDED Clinical features were early loss of teeth, bowed legs diagnosed as rickets and requiring osteotomy, and beaten-copper appearance of skull x-ray. The propositus had served in the U.S. Air Force. Danovitch et al. (1968) also suggested dominant inheritance as the mechanism...

#241510 HYPOPHOSPHATASIA, CHILDHOOD Gene map locus 1p36.1-p34 childhood hypophosphatasia is caused by mutation in the ALPL gene (171760). As indicated in 241500, at least 2 varieties of recessive hypophosphatasia occur, i.e., the severe infantile (congenital) and the relatively mild childhood forms; the 2 forms are probably allelic (Henthorn et al., 1992). See...

Initially recognized by Rathbun in 1948, hypophosphatasia is a rare inborn error of metabolism. Low activity of the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP), which leads to rickets, osteomalacia, or both, characterize this disorder. Incidence has been estimated at 1 per 100,000 births. Clinical presentation varies widely, from death in...

Hypophosphatasia may cause or feature Miscellaneous syndromes Nephrocalcinosis Osteomalacia Pathological fracture Symptoms and Signs Blue sclerae Disproportionate short stature Genu varum Tooth loss Biochemical abnormalities Alkaline phosphatase levels low (plasma or serum) Hypercalcaemia Hypercalciuria Congenital conditions Craniosynostosis Inflammatory conditions Pyrophosphate arthropathy may be allelic with Phosphoethanolaminuria Autosomal recessive condition Hypophosphatasia: "A genetic metabolic disorder resulting from serum and bone alkaline phosphatase deficiency leading to hypercalcemia, ethanolamine phosphatemia, and ethanolamine phosphaturia. Clinical...

Hypophosphatasia is a rare disorder, genetically transmitted in an autosomal recessive pattern, and is characterized by defective skeletal mineralization resembling that of rickets and osteomalacia. It results in abnormal mineralization of bone, low serum alkaline phosphatase levels (only bone and liver isoenzymes) and abnormal levels of phosphorylethanolamine in the urine...

Objectives
1. Describe the mode of transmission and enzymatic defect noted in patients with hypophosphatasia
2. Describe physical findings noted in patients with hypophosphatasia
3. Discuss laboratory findings in patients with hypophosphatasia
4. Describe radiographic features of hypophosphatasia

Wheeless' Textbook of Orthopaedics Discussion: - this is the most frequently encountered form of rickets and consists of a genetic or acquired fault in the handling of phosphate in the proximal tubule; -...

#241500 HYPOPHOSPHATASIA, INFANTILE Alternative titles; symbols HOPS PHOSPHOETHANOLAMINURIA Gene map locus 1p36.1-p34 CONTRIBUTORS Cassandra L. Kniffin - updated : 8/11/2004 Ada Hamosh - updated : 9/22/2003 Victor A. McKusick - updated : 10/14/1998