Congenital secretory chloride diarrhea is an autosomal recessive form of severe chronic diarrhea characterized by excretion of large amounts of watery stool containing high levels of chloride, resulting in dehydration, hypokalemia, and metabolic alkalosis. The electrolyte disorder resembles the renal disorder Bartter syndrome (see 607364), except that chloride diarrhea is not associated with calcium level abnormalities (summary by Choi et al., 2009). Genetic Heterogeneity of Diarrhea Other forms of diarrhea include DIAR2 (251850), caused by mutation in the MYO5B gene (606540) on 18q21; DIAR3 (270420), caused by mutation in the SPINT2 gene (605124) on 19q13; DIAR4 (610370), caused by mutation in the NEUROG3 gene (604882) on 10q21; DIAR5 (613217), caused by mutation in the EPCAM gene (185535) on 2p21; DIAR6 (614616), caused by mutation in the GUCY2C gene (601330) on 12p12; DIAR7 (615863) caused by mutation in the DGAT1 gene (604900) on 8q24; DIAR8 (616868), caused by mutation in the SLC9A3 gene (182307) on 5p15; DIAR9 (618168), caused by mutation in the WNT2B gene (601968) on 1p13; DIAR10 (618183), caused by mutation in the PLVAP gene (607647) on 19p13; DIAR11 (618662), caused by deletion of the intestine critical region (ICR) on chromosome 16p13, resulting in loss of expression of the flanking gene PERCC1 (618656); DIAR12 (619445), caused by mutation in the STX3 gene (600876) on 11q12; and DIAR13 (620357), caused by mutation in the ACSL5 gene (605677) on chromosome 10q25.

Apparent mineralocorticoid excess (AME) is an autosomal recessive form of low-renin hypertension associated with low aldosterone, metabolic alkalosis, hypernatremia, and hypokalemia. The disorder is due to a congenital defect in 11-beta-hydroxysteroid dehydrogenase type II (HSD11B2) activity, resulting in decreased conversion of biologically active cortisol to inactive cortisone; this defect allows cortisol to act as a ligand for the mineralocorticoid receptor, resulting in sodium retention and volume expansion. There is a favorable therapeutic response to spironolactone (review by Ferrari, 2010).

Generalized glucocorticoid resistance is an autosomal dominant disease characterized by increased plasma cortisol concentration and high urinary free cortisol, resistance to adrenal suppression by dexamethasone, and the absence of clinical stigmata of Cushing syndrome. The clinical expression of the disease is variable. Common features include hypoglycemia, hypertension, and metabolic alkalosis. In females, overproduction of adrenal androgens has been associated with infertility, male-pattern baldness, hirsutism, and menstrual irregularities. Other features include chronic fatigue and profound anxiety (summary by Chrousos et al., 1983; Donner et al., 2013).

A rare, genetic, neurologic disease characterized by primary hyperaldosteronism presenting with early-onset, severe hypertension, hypokalemia and neurological manifestations (including seizures, severe hypotonia, spasticity, cerebral palsy and profound developmental delay/intellectual disability).

Combined oxidative phosphorylation deficiency-24 (COXPD24) is an autosomal recessive mitochondrial disorder with wide phenotypic variability. Most patients present in infancy with delayed neurodevelopment, refractory seizures, hypotonia, and hearing impairment due to auditory neuropathy. Less common features may include cortical blindness, renal dysfunction, and/or liver involvement, suggestive of Alpers syndrome (MTDPS4A; 203700). Patients with the severe phenotype tend to have brain abnormalities on imaging, including cerebral atrophy and hyperintensities in the basal ganglia and brainstem, consistent with Leigh syndrome. Laboratory values may be normal or show increased lactate and evidence of mitochondrial respiratory chain defects, particularly in muscle. Some patients achieve little developmental milestones and may die in infancy or early childhood. However, some patients have a less severe phenotype manifest only by myopathy (summary by Sofou et al., 2015, Vanlander et al., 2015, and Mizuguchi et al., 2017). For a discussion of genetic heterogeneity of combined oxidative phosphorylation deficiency, see COXPD1 (609060).

Liddle syndrome is an autosomal dominant form of hypertension characterized by early onset of hypertension associated with hypokalemia, suppressed plasma renin activity, and suppressed secretion of the mineralocorticoid hormone aldosterone (summary by Hansson et al., 1995). For a general phenotypic description and a discussion of genetic heterogeneity of Liddle syndrome, see 177200.

Liddle syndrome, or pseudoaldosteronism, is an autosomal dominant form of salt-sensitive hypertension characterized by suppressed plasma renin and aldosterone, hypokalemia, and metabolic alkalosis (summary by Salih et al., 2017). For a discussion of genetic heterogeneity of Liddle syndrome, see 177200.