Scientific background:

Summary: Dentin matrix acidic phosphoprotein is an extracellular matrix protein and a member of the small integrin binding ligand N-linked glycoprotein family. This protein, which is critical for proper mineralization of bone and dentin, is present in diverse cells of bone and tooth tissues. The protein contains a large number of acidic domains, multiple phosphorylation sites, a functional arg-gly-asp cell attachment sequence, and a DNA binding domain. In undifferentiated osteoblasts it is primarily a nuclear protein that regulates the expression of osteoblast-specific genes. During osteoblast maturation the protein becomes phosphorylated and is exported to the extracellular matrix, where it orchestrates mineralized matrix formation. Mutations in the gene are known to cause autosomal recessive hypophosphatemia, a disease that manifests as rickets and osteomalacia. The gene structure is conserved in mammals. Two transcript variants encoding different isoforms have been described for this gene. [provided by RefSeq]

Methodology:

	clinical test	Method		Genomic sequencing of the entire coding region
		Turn-around time		25 working days
		Effort		little
		Specimen		DNA
		Quality assessment		Internal quality control only
	All known and new missense, nonsense and splice mutations can be detected.
	clinical test	Method		Carrier testing
		Turn-around time		5 working days
		Effort		little
		Specimen		DNA
		Quality assessment		Internal quality control only
	The test is only specific about the mutation already known in this kindred.

Literature: 

Aplin HM et al. (1995) Mapping of the human dentin matrix acidic phosphoprotein gene (DMP1) to the dentinogenesis imperfecta type II critical region at chromosome 4q21.
Feng JQ et al. (2006) Loss of DMP1 causes rickets and osteomalacia and identifies a role for osteocytes in mineral metabolism.
George A et al. (1993) Characterization of a novel dentin matrix acidic phosphoprotein. Implications for induction of biomineralization.
Hirst KL et al. (1997) Elucidation of the sequence and the genomic organization of the human dentin matrix acidic phosphoprotein 1 (DMP1) gene: exclusion of the locus from a causative role in the pathogenesis of dentinogenesis imperfecta type II.
Ling Y et al. (2005) DMP1 depletion decreases bone mineralization in vivo: an FTIR imaging analysis.
Lorenz-Depiereux B et al. (2006) DMP1 mutations in autosomal recessive hypophosphatemia implicate a bone matrix protein in the regulation of phosphate homeostasis.
MacDougall M et al. (1996) Assignment of DMP1 to human chromosome 4 band q21 by in situ hybridization.