Syndromes associated with low blood pressure |
Gitelman syndrome |
SLC12A3 |
Adolescence or adulthood |
Loss-of-function mutations in the gene encoding the thiazide-sensitive Na–Cl cotransporter of the distal collecting duct causes salt wasting and activation of the renin–angiotensin–aldosterone system. Thereby maintenance of serum sodium but loss of potassium and H+ by augmentation of the epithelial sodium channel |
Hypokalaemia with metabolic alkalosis. Low serum Mg2+ and low urinary Ca2+ levels |
[103,104] |
16q3 |
Bartter syndrome |
|
|
|
Often associated with preterm delivery. In contrast to Gitelman syndrome, normal or only mildly reduced serum Mg2+ and increased urinary Ca2+ levels |
|
Type 1 |
SLC12A |
Neonatal |
Loss of function of the apical Na–K–2Cl cotransporter |
|
[105] |
15q21 |
Type 2 |
KCNJ1 |
Neonatal |
Mutations of the ATP-sensitive K+ channel ROMK affect K+ recycling and thereby inhibit Na+ reabsorption in the thick ascending limb of Henle |
|
[106] |
11q24 |
Type 3 |
CLCNKB |
School age |
Loss-of-function mutations in the Cl− channel CLCNKB in the thick ascending limb of Henle. Some of these mutations have arisen from unequal crossing over between CLCNKB and the nearby related gene CLCNKA
|
|
[107] |
1p36 |
Type 4 |
BSND |
Neonatal |
BSND encodes Barttin which functions as a beta-subunit for CLCNKA and CLCNKB chloride channels |
Associated with sensorineural deafness. inhibition of NaCl reabsorption in type IV Bartter syndrome is not restricted to the thick ascending limb of Henle |
[108] |
1p32 |
Type 5 |
CASR |
Adulthood |
Mutations activating the calcium-sensing receptor CaSR which then inhibits sodium transport in the thick ascending limb of the loop of Henle |
Associated with autosomal dominant hypocalcaemia (ADH) |
[109] |
3q13 |
Autosomal dominant pseudohypoaldosteronism type I |
NR3C2 |
Neonatal |
Loos/of/function mutations in the mineralocorticoid receptor impairing maximum salt absorption. The reduced activity of the endothelial sodium channel affects H+ and K+ excretion |
Salt wasting with hypotension despite markedly elevated aldosterone levels; hyperkalemia and metabolic acidosis. Often asymptomatic in adulthood on usual western (high salt) diet |
[110,111] |
4q31 |
Recessive pseudohypoaldosteronism type I |
SCNN1A |
Neonatal |
Loss-of-function mutations in any of the three different subunits of the epithelial sodium channel |
Salt wasting and hypotension with hyperkalemia and metabolic acidosis, despite high levels of aldosterone. Require high dose salt supplementation |
[112] |
16p12 |
SCNN1B |
12p13 |
SCNN1G |
16p12 |
|
Syndromes associated with high blood pressure |
Glucorticoid-remediable aldosteronism |
CYP11B2 and CYP11B1
|
Second or third decade |
Gene duplication due to unequal crossing over between the aldosterone synthase (CYP11B2) and steroid 11β-hydroxylase (CYP11B1) genes. The resulting chimaeric gene encodes a protein under the regulation of ACTH with aldosterone synthase activity |
Normal or elevated aldosterone levels despite suppressed plasma renin activity. Hypokalaemia and metabolic alkalosis are variable associated findings. Exogenous glucocorticoids completely suppress aldosterone secretion |
[113–116] |
8q21 |
Apparent mineralocorticoid excess |
HSD11B2 |
Childhood |
Absence of the enzyme 11β-hydroxysteroid dehydrogenase allows cortisol to activate MR, resulting in hypertension mediated by increased epithelial sodium channel activity |
Hypokalaemia and metabolic alkalosis accompanied by suppressed plasma renin activity and the virtual absence of circulating aldosterone |
[117,118] |
16q22 |
Hypertension exacerbated in pregnancy |
NR3C2 |
Before second decade |
Missense mutation, S810L, in the mineralocorticoid receptor causing normal activation by aldosterone but also activation by ligands that are normally silent or antagonistic (e.g. progesterone) |
Exacerbation during pregnancy due to the increased progesterone levels |
[119] |
4q31 |
Liddle syndrome |
SCNN1B |
Adolescence |
Mutations in either the β or the γ subunit of the epithelial sodium channel delete their cytoplasmic C termini and result in increased channel activity |
Associated with hypokalaemic alkalosis, suppressed plasma renin activity, and low plasma aldosterone levels |
[120–122] |
12p13 |
SCNN1G |
16p12 |
Pseudohyperaldosteronism type II (Gordon syndrome) |
WNK1, 12p13 |
Second or third decade |
WNK kinases are expressed in the distal nephron and are involved in the control of renal electrolyte homeostasis |
Hyperkalaemia and low aldosterone levels. Sensitive to treatment with thiazide diuretics |
[95,98] |
WNK4, 17q21 |