|
Channel kinase 2
Scientific background:
Summary: Mutations of this gene cause enteral and renal magnesium losses.
Gene: The gene is 199 kb in size. It is known as TRPM6 and CHAK2. It is located on chromosome 9 at position 9q22. It consists of 39 exons. the first exon is not translated.
Pathology: The translation product a protein of 2,022 amino acids (234 kD). It consists of a predicted ion channel domain and a protein kinase domain. The gene is expressed in enteral and renal epithelium cells. Obviously its function is connected to magnesium absorption.
Clinical signs: Hypomagnesemia is the main symptom. It occurs in conjunction with a secondary hypocalcemia. Often the disturbance of enteral magnesium resorption leads to diarrhea. Neurologically, convulsions and tetany dominate the clinical picture. By the pathologist calcinosis is found in several organs including myocardium, kidneys, and cerebral arteries.
Epidemiology: Epidemiological data does not yet exist.
Interpretation: Limited data exist for genotype phenotype correlation. If a mutation of this gene was detected, one would stop oral magnesium supplementation to not aggravate the gastrointestinal symptoms.
Test strategy: Predominant indications for molecular diagnostic are family counseling and improvement of diagnostic precision.
Methodology:
|
clinical
test |
Method |
Genomic sequencing of the entire coding region |
| Turn-around time |
25 working days |
| Effort |
large |
| 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. |
|
