MedGen

Primary hyperoxaluria is an autosomal recessive disorder of glyoxylate metabolism that results in excessive endogenous oxalate synthesis and the formation of calcium oxalate kidney stones. Progressive renal inflammation and interstitial fibrosis from advanced nephrocalcinosis, recurrent urolithiasis, and urinary tract infections can cause reduced renal function, systemic oxalate deposition, and end-stage renal failure. Compared to hyperoxaluria type I (HP1; 259900) and type II (HP2; 260000), HP3 appears to be the least severe, with good preservation of kidney function in most patients. The typical clinical characteristic is early onset of recurrent urolithiasis, but less active stone formation later (summary by Wang et al., 2015). For a discussion of genetic heterogeneity of primary hyperoxaluria, see 259900. [from OMIM]

Abnormally increased level of blood lactate (2-hydroxypropanoic acid). Lactate is produced from pyruvate by lactate dehydrogenase during normal metabolism. The terms lactate and lactic acid are often used interchangeably but lactate (the component measured in blood) is strictly a weak base whereas lactic acid is the corresponding acid. Lactic acidosis is often used clinically to describe elevated lactate but should be reserved for cases where there is a corresponding acidosis (pH below 7.35). [from HPO]

Esomeprazole (brand name Nexium) is a proton pump inhibitor (PPI) used to treat gastroesophageal reflux disease (GERD) and to reduce the risk of gastric ulcers associated with nonsteroidal anti-inflammatory drug NSAID use. Esomeprazole is also used in the treatment of hypersecretory conditions, such as Zollinger-Ellison syndrome, and in combination with antibiotics to eradicate Helicobacter pylori (H. pylori) infection. Esomeprazole reduces the acidity (raises the pH) in the stomach by inhibiting the secretion of gastric acid. The level of esomeprazole an individual is exposed to is influenced by several factors, such as the dose used and how quickly the drug is metabolized and inactivated. Esomeprazole is primarily metabolized by the CYP2C19 enzyme. Individuals with increased CYP2C19 enzyme activity (“CYP2C19 ultrarapid metabolizers”) may have an insufficient response to standard doses of esomeprazole, because the drug is inactivated at a faster rate. In contrast, individuals who have reduced or absent CYP2C19 enzyme activity (i.e., CYP2C19 intermediate and poor metabolizers) have a greater exposure to esomeprazole. The 2018 FDA-approved drug label for esomeprazole states that 3% of Caucasians, and 15–20% of Asians are CYP2C19 poor metabolizers, and that poor metabolizers have approximately twice the level of exposure to esomeprazole, compared with CYP2C19 normal metabolizers. However, the drug label does not include dosing recommendations for CYP2C19 poor metabolizers. Esomeprazole recommendations have been published by the Dutch Pharmacogenetics Working Group (DPWG) of the Royal Dutch Association for the Advancement of Pharmacy (KNMP), which indicates that no change in dosing is recommended for CYP2C19 poor, intermediate, or ultrarapid metabolizers. The DPWG states that although genetic variation in CYP2C19 influences the plasma concentration of esomeprazole, there is insufficient evidence to support an effect on treatment outcomes or side effects. [from Medical Genetics Summaries]

Chloroquine is used for the treatment of uncomplicated malaria and extra-intestinal amebiasis. Malaria is caused by infection of Plasmodium parasites. Chloroquine is active against the erythrocytic forms of susceptible strains of Plasmodium falciparum (P. falciparum), Plasmodium malariae (P. malariae), Plasmodium ovale (P. ovale), and Plasmodium Vivax (P. vivax). Chloroquine is not active against the gametocytes and the exoerythrocytic forms including the hypnozoite stage (P. vivax and P. ovale) of the Plasmodium parasites. Additionally, resistance to chloroquine and hydroxychloroquine has been reported in Plasmodium species, thus chloroquine therapy is not indicated if the infection arose in a region with known resistance. Chloroquine is used in first-line treatment of P. vivax malaria with primaquine. Studies have indicated chloroquine is effective against the trophozoites of Entamoeba histolytica (E. histolytica), which causes amebic dysentery, or amebiasis. Chloroquine also has off-label uses for treatment of rheumatic diseases and has been investigated as a potential antiviral therapy as well as an adjuvant chemotherapy for several types of cancer. Chloroquine accumulates in cellular acidic compartments such as the parasitic food vacuole and mammalian lysosomes, leading to alkalinization of these structures. This change in pH can impair the action of enzymes responsible for the formation of hemozoin by the parasite from ingestion of the host’s hemoglobin; this reaction occurs in the parasitic vacuole. Thus, chloroquine targets the blood-stage of the malaria parasites but cannot eliminate dormant hypnozoites and must be administered with a drug that targets the dormant parasitic form. Chloroquine, developed in the 1940s, has been superseded as the first-line recommended antimalarial therapy by both the US Centers for Disease Control (CDC) and World Health Organization (WHO), with the exceptions of during the first trimester of pregnancy or for malarial prophylaxis of a pregnant individual who is also deficient for glucose-6-phosphate dehydrogenase (G6PD). Among antimalarial medications, chloroquine is less likely than other medicines to cause hemolysis in G6PD-deficient individuals; however, the FDA-approved drug label states there is still a risk of hemolysis. In contrast, the Clinical Pharmacogenetics Implementation Consortium (CPIC) performed a systematic review of the available clinical literature and found low-to-no risk of acute hemolytic anemia for individuals with G6PD deficiency who take hydroxychloroquine or chloroquine. It should be noted that G6PD deficiency has a range of severity; CPIC advises caution for all medications when used by an individual with a severe G6PD deficiency with chronic non-spherocytic hemolytic anemia (CNSHA). [from Medical Genetics Summaries]

Helicobacter pylori is a microaerophilic, gram-negative bacterium that colonizes the gastric mucosa of approximately 50% of the world's population, and is a primary pathogenic factor in benign and malignant gastroduodenal disease (Warren and Marshall, 1983; Blaser and Parsonnet, 1994). Tomb et al. (1997) reported the complete sequence of the circular genome of H. pylori. The 1,667,867-bp genome contains 1,590 predicted coding sequences (genes). Sequence analysis of these genes indicated that the organism has systems for motility, for scavenging iron, and for DNA restriction and modification. Its survival in acid conditions depends, in part, on its ability to establish a positive inside-membrane potential in low pH. [from OMIM]

Excretion of urine with an acid pH, i.e., having an increased hydrogen ion concentration. [from HPO]

The kidney contributes towards acid-base homeostasis by excreting H+ ions and retaining bicarbonate. This process is known as acidification of the urine. The pH of urine ranges normally from 4.5 to 8. The inability to reduce the pH of the urine in a situation where it would be otherwise expected is known as an acidification defect. [from HPO]

Metabolic acidosis (MA) is characterized by a fall in blood pH due to a reduction of serum bicarbonate concentration. This can occur as a result of either the accumulation of acids (high anion gap MA) or the loss of bicarbonate from the gastrointestinal tract or the kidney (hyperchloremic MA). By definition, MA is not due to a respirary cause. [from HPO]

Liddle syndrome is an inherited form of high blood pressure (hypertension). This condition is characterized by severe hypertension that begins unusually early in life, often in childhood, although some affected individuals are not diagnosed until adulthood. Some people with Liddle syndrome have no additional signs or symptoms, especially in childhood. Over time, however, untreated hypertension can lead to heart disease or stroke, which may be fatal.

In addition to hypertension, affected individuals can have low levels of potassium in the blood (hypokalemia). Signs and symptoms of hypokalemia include muscle weakness or pain, fatigue, constipation, or heart palpitations. The shortage of potassium can also raise the pH of the blood, a condition known as metabolic alkalosis. [from MedlinePlus Genetics]

Autosomal dominant hypocalcemia is characterized by low levels of calcium in the blood (hypocalcemia). Affected individuals can have an imbalance of other molecules in the blood as well, including too much phosphate (hyperphosphatemia) or too little magnesium (hypomagnesemia). Some people with autosomal dominant hypocalcemia also have low levels of a hormone called parathyroid hormone (hypoparathyroidism). This hormone is involved in the regulation of calcium levels in the blood. Abnormal levels of calcium and other molecules in the body can lead to a variety of signs and symptoms, although about half of affected individuals have no associated health problems.

The most common features of autosomal dominant hypocalcemia include muscle spasms in the hands and feet (carpopedal spasms) and muscle cramping, prickling or tingling sensations (paresthesias), or twitching of the nerves and muscles (neuromuscular irritability) in various parts of the body. More severely affected individuals develop seizures, usually in infancy or childhood. Sometimes, these symptoms occur only during episodes of illness or fever.

Some people with autosomal dominant hypocalcemia have high levels of calcium in their urine (hypercalciuria), which can lead to deposits of calcium in the kidneys (nephrocalcinosis) or the formation of kidney stones (nephrolithiasis). These conditions can damage the kidneys and impair their function. Sometimes, abnormal deposits of calcium form in the brain, typically in structures called basal ganglia, which help control movement.

A small percentage of severely affected individuals have features of a kidney disorder called Bartter syndrome in addition to hypocalcemia. These features can include a shortage of potassium (hypokalemia) and magnesium and a buildup of the hormone aldosterone (hyperaldosteronism) in the blood. The abnormal balance of molecules can raise the pH of the blood, which is known as metabolic alkalosis. The combination of features of these two conditions is sometimes referred to as autosomal dominant hypocalcemia with Bartter syndrome or Bartter syndrome type V.

There are two types of autosomal dominant hypocalcemia distinguished by their genetic cause. The signs and symptoms of the two types are generally the same. [from MedlinePlus Genetics]

Metabolic alkalosis is defined as a disease state where the pH is elevated to greater than 7.45 secondary to some metabolic process. [from HPO]

A type of renal tubular acidosis characterized by a failure of acid secretion by the alpha intercalated cells of the cortical collecting duct of the distal nephron. The urine cannot be acidified below a pH of 5.3, associated with acidemia and hypokalemia. [from HPO]

An increased level of a dibasic amino acid in the urine. Dibasic amino acids are usually refered to simply as basic aminoacids because they contain basic side chains at neutral pH. These are arginine (Arg), lysine (Lys), and histidine (His). [from HPO]

Increase in blood LACTATE concentration often associated with SEPTIC SHOCK; LUNG INJURY; SEPSIS; and DRUG TOXICITY. When hyperlactatemia is associated with low body pH (acidosis) it is LACTIC ACIDOSIS. [from MeSH]

Acidosis (pH less than 7.35) that develops with an increase in ionic chloride. [from HPO]

An abnormality of the balance or maintenance of the balance of acids and bases in bodily fluids, resulting in an abnormal pH. [from HPO]

Longstanding impairment in ventilation such that the partial pressure of carbon dioxide (PaCO2) is elevated above the upper limit of the reference range (more than 45 mm Hg), with a normal or near-normal pH secondary to renal compensation and an elevated serum bicarbonate levels (more than30 mEq/L). [from HPO]

Sudden onset of impairment in ventilation such that the removal of carbon dioxide by the respiratory system is less than the production of carbon dioxide in the tissues, leading to an elevation of the partial pressure of carbon dioxide (PaCO2) above the normal limits (more than 45 mm Hg) with an accompanying acidemia (pH less than 7.35). [from HPO]

A rare progressive and life-threatening anomaly of the great vessels characterized by narrowing and obstruction of one or more normally positioned pulmonary vein at their junction with the left atrium. Presentation is typically during early infancy with dyspnea, tachypnea, and repeated pulmonary infections. Eventually, when all pulmonary veins of one lung are affected, the disorder results in pulmonary hypertension (PH) and consecutive pulmonary arterial hypertension (PAH). It may manifest as an isolated lesion or associated with other cardiac defects such as congenital pulmonary venous return anomaly and septal defects. [from ORDO]

A myeloproliferative disorder characterized by increased proliferation of the granulocytic cell line without the loss of their capacity to differentiate. [from HPO]