Laboratory for Molecular Diagnostics
Center for Nephrology and Metabolic Disorders

Hypomagnesemia

The cardinal symptom of this group of diseases is hypomagnesemia. The specific diseases of this group differ by severity and accompanying symptoms.

Test Strategy

The extend of magnesium waste can by measured by clamp experiments in which serum magnesium has to be supplemented until steady state conditions have been established and serum concentration remains normal. All the other electrolytes have to be normalized too. In this steady state condition the renal loss can be quantified and related to oral or parenteral substitution.

Additionally, the following signs have to be considered: family history: autosomal dominant, recessive, x-linked, or de novo mutation; age of onset; accompanying symptoms: acid base disorders, disturbances in calcium balance, diarrhea or other hints about distrurbed enteral absorption; neurological symptoms: cramps, seizures, convulsion, tetany; hormonal disturbances: parathormon, glucagon, calcitonin, vitamin-D, ADH; intoxications: diuretics.

Pathogenesis

The loss of magnesium mainly occurs in the kidneys. The distal convoluted tubule reabsorbs the bulk of glomerular filtered magnesium. If enteral absorption is also altered, diarrhea may result. Hypomagnesemia can also develop in conjunction wit other electrolyte disturbances.

Systematic

Hereditary Salt-wasting tubulopathies
Bartter syndrome
EAST syndrome
Gitelman syndrome
Hypomagnesemia
EGFR
Gitelman syndrome
SLC12A3
Hereditary myokymia type 1
KCNA1
Hypomagnesemia with hypercalciuria and nephrocalcinosis
CLDN16
Hypomagnesemia with hypercalciuria and nephrocalcinosis with ocular involvement
CLDN19
Hypomagnesemia with normocalciuria
EGF
Intestinal hypomagnesemia with secondary hypocalcemia
TRPM6
Isolated dominant hypomagnesemia
FXYD2
Renal cysts and diabetes (RCAD)
HNF1B
Renal hypomagnesemia 6
CNNM2
TRPM7

References:

1.

Dai LJ et al. (2001) Magnesium transport in the renal distal convoluted tubule.

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2.

Konrad M et al. (2003) Recent advances in molecular genetics of hereditary magnesium-losing disorders.

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3.

Orphanet article

Orphanet ID 31043 [^]
4.

Wikipedia article

Wikipedia EN (Magnesium_deficiency) [^]
Update: April 29, 2019