237 articles
Neonatal adrenoleukodystrophy
Neonatal adrenoleukodystrophy (NALD), also called intermediate Zellweger spectrum disorder, is an autosomal recessive peroxisome biogenesis disorder (PEX genes, OMIM 202370) marked by hypotonia, leukodystrophy, hearing and vision loss, VLCFA accumulation, and adrenal atrophy.
Neonatal intrahepatic cholestasis due to citrin deficiency
NICCD (neonatal intrahepatic cholestasis caused by citrin deficiency) is the neonatal phenotype of autosomal recessive SLC25A13/citrin deficiency, causing cholestasis, hypercitrullinemia, and hypoglycemia in infants, treated with lactose-free MCT-enriched formula and fat-soluble vitamins.
Nicotine poisoning
Nicotine poisoning: toxic effects of nicotine swallowed, inhaled, or absorbed through skin or eyes, mainly from e-liquids; two-phase vomiting-to-paralysis syndrome, no antidote, children under 6 most affected.
Niemann-Pick disease type C
Niemann-Pick disease type C (NPC, NPCD) is a rare autosomal recessive lysosomal storage disorder caused by NPC1 (95%) or NPC2 mutations, impairing intracellular cholesterol transport; it causes age-dependent ataxia, dementia, and early death, treated with miglustat, arimoclomol, and levacetylleucine.
Niemann–Pick disease
Niemann-Pick disease (NPD), also called sphingomyelinase deficiency, is a group of autosomal recessive lysosomal lipid storage disorders: types A/B from SMPD1 acid sphingomyelinase deficiency and type C from NPC1/NPC2 cholesterol-transport defects, treated with olipudase alfa, miglustat, arimoclomol, and levacetylleucine.
Ogden syndrome
Ogden syndrome (NAA10-related Ogden syndrome) is a rare X-linked recessive infantile-lethal disorder caused by the recurrent NAA10 Ser37Pro variant, impairing the NatA acetyltransferase complex, with growth delay, hypotonia, aged facies, and cardiac arrhythmia.
Oxoglutaric aciduria
Oxoglutaric aciduria, or alpha-ketoglutarate dehydrogenase deficiency (OMIM 203740), is a very rare autosomal recessive TCA cycle disorder caused by OGDH variants on 7p13, presenting neonatally with hypotonia, seizures, lactic acidemia, and elevated urinary alpha-ketoglutaric acid, distinct from 2-hydroxyglutaric acidurias and glutaric aciduria type I.
PAICS deficiency
PAICS deficiency (phosphoribosylaminoimidazole carboxylase deficiency, OMIM 619859) is a rare autosomal recessive error of de novo purine synthesis causing fatal neonatal malformations or later-onset neurodevelopmental disease.
Paraneoplastic syndrome
Paraneoplastic syndrome: remote effects of cancer, also called PNS, caused by tumor-secreted hormones or cross-reactive immune responses, affecting endocrine, neurologic, cutaneous, hematologic, and other systems, often preceding cancer diagnosis.
Peroxisomal acyl-CoA oxidase deficiency
Peroxisomal acyl-CoA oxidase deficiency, also called pseudo-neonatal adrenoleukodystrophy (pseudo-NALD), is a rare autosomal recessive ACOX1 (17q25.1) disorder of peroxisomal VLCFA beta-oxidation causing neonatal hypotonia, seizures, and regression, distinct from Mitchell syndrome (dominant ACOX1 gain-of-function).
PGM1-CDG
PGM1-CDG (CDG-It, GSD XIV, OMIM 614921) is a rare autosomal recessive disorder of phosphoglucomutase 1 deficiency causing mixed glycogen storage and glycosylation disease, treated with D-galactose.
Phenylketonuria
Phenylketonuria (PKU), also Fölling disease, an autosomal recessive PAH-gene disorder causing phenylalanine buildup; treated by Phe-restricted diet, sapropterin, pegvaliase, and sepiapterin, detected by Guthrie newborn screening.
Phosphoenolpyruvate carboxykinase deficiency
Phosphoenolpyruvate carboxykinase deficiency (PEPCK deficiency, PEPCK-C deficiency, PCK1/PCK2) is an ultra-rare autosomal recessive gluconeogenesis disorder causing recurrent fasting hypoglycemia, lactic acidosis, liver failure, and TCA-cycle metabolites in urine.
Phosphoribosylpyrophosphate synthetase superactivity
Phosphoribosylpyrophosphate synthetase superactivity (PRS superactivity, PRPS1 superactivity) is a rare X-linked purine metabolism disorder causing hyperuricemia, gout, and uric acid stones, with a severe early-onset form adding deafness and neurologic impairment.
PLIN1-related familial partial lipodystrophy
PLIN1-related familial partial lipodystrophy (FPLD4, OMIM 613877) is a rare autosomal dominant lipodystrophy caused by frameshift variants in PLIN1, which encodes perilipin-1, marked by lower-limb and gluteal fat loss, muscular hypertrophy, insulin resistance, and hypertriglyceridemia.
Polyglucosan body myopathy type 1
Polyglucosan body myopathy type 1 (PGBM1, OMIM 615895) is an ultrarare autosomal recessive glycogen storage disorder caused by RBCK1 mutations, causing childhood proximal muscle weakness, dilated cardiomyopathy, and sometimes immunodeficiency.
Porphyria due to ALA dehydratase deficiency
Porphyria due to ALA dehydratase deficiency (ALAD porphyria, Doss porphyria, plumboporphyria): ultra-rare autosomal recessive acute hepatic porphyria, fewer than a dozen cases, elevated urinary ALA with normal PBG, ALAD gene 9q32.
PPARG-related familial partial lipodystrophy
PPARG-related familial partial lipodystrophy (FPLD3, OMIM 604367) is a rare autosomal dominant lipodystrophy from loss-of-function PPARG variants, causing limb lipoatrophy, truncal fat gain, diabetes, and hypertriglyceridemia.
Primary hypercholesterolaemia
Primary hypercholesterolaemia (ICD-11 5C80.00): genetically driven high cholesterol, including familial hypercholesterolaemia (LDLR, APOB, PCSK9) and polygenic forms, distinguished from secondary causes and treated with statins.
Primary hyperoxaluria
Primary hyperoxaluria (PH1, PH2, PH3; AGXT, GRHPR, HOGA1) is a rare autosomal recessive liver enzyme disorder causing oxalate overproduction, recurrent calcium oxalate stones, kidney failure, and systemic oxalosis; treated with pyridoxine, RNAi drugs lumasiran and nedosiran, and transplantation.
Prolidase deficiency
Prolidase deficiency (hyperimidodipeptiduria, OMIM 170100): autosomal recessive PEPD gene disorder causing chronic leg ulcers, recurrent infections, facial dysmorphism, intellectual disability, and splenomegaly; prevalence about 1 in 1,235,000.
Pyruvate carboxylase deficiency
Pyruvate carboxylase deficiency (PC deficiency), a rare autosomal recessive disorder of the PC gene at 11q13.4-q13.5, causing lactic acidosis; types A, B, and C differ in severity.
Pyruvate dehydrogenase deficiency
Pyruvate dehydrogenase deficiency (PDHD, PDCD) is a genetic mitochondrial disorder impairing conversion of pyruvate to acetyl-CoA, causing congenital lactic acidosis and neurological degeneration; mostly X-linked PDHA1, treated with ketogenic diet and dichloroacetate.
Ravine syndrome
Ravine syndrome, also called RAVINE leukoencephalopathy, is an extremely rare autosomal recessive genetic neurological disorder described on Reunion Island, causing infantile anorexia, intractable vomiting, and progressive encephalopathy.
Rochelle Hirschhorn
Rochelle Hirschhorn is an American medical geneticist at NYU Langone who led its medical genetics division for 24 years, explained ADA deficiency, cloned the Pompe disease gene, and shared the 2013 McKusick Leadership Award.
S-adenosylhomocysteine hydrolase deficiency
S-adenosylhomocysteine hydrolase deficiency (AHCY deficiency, SAHH deficiency) is a rare autosomal recessive methionine metabolism disorder causing elevated SAH, SAM, myopathy, liver dysfunction, and developmental delay, with roughly 15 reported cases.
Saccharopinuria
Saccharopinuria (hyperlysinemia type II, saccharopine dehydrogenase deficiency, OMIM 268700) is a rare autosomal recessive lysine catabolism disorder from an AASS SDH-domain defect, causing elevated blood and CSF lysine and urinary saccharopine.
Sarcosinemia
Sarcosinemia (hypersarcosinemia, sarcosine dehydrogenase deficiency, OMIM 268900) is a rare autosomal recessive inborn error of metabolism with elevated sarcosine in plasma and urine due to SARDH deficiency; considered benign.
Secondary gout
Secondary gout, also called secondary hyperuricemia-related gout, is gout arising during another disease or from drugs, via purine overproduction, nucleic acid turnover, or reduced renal urate clearance; ICD-11 codes FA25.1 include lead- and drug-induced forms.
Secondary hypercholesterolaemia
Secondary hypercholesterolaemia (acquired hypercholesterolemia, ICD-11 5C80.01) is elevated LDL cholesterol caused entirely by another condition or drug, chiefly hypothyroidism, nephrotic syndrome, cholestasis, pregnancy, ketogenic or high-saturated-fat diets, and agents like thiazides, cyclosporine, and corticosteroids.