Human health and medicine

Acquired von Willebrand syndrome

Acquired von Willebrand syndrome (AVWS, aVWS) is a rare, non-inherited bleeding disorder from acquired VWF defects, mostly due to lymphoproliferative, myeloproliferative, or cardiovascular disease, with low VWF activity-to-antigen ratios and loss of high-molecular-weight multimers.

ACR246

ACR246 (ACR-246, ADC2154) is an anti-5T4 antibody-drug conjugate with a topoisomerase I inhibitor payload D-2102, DAR 8, developed by Hangzhou Adcoris Biopharma; in Phase I/IIa trials in China and licensed globally to K2 Therapeutics in 2026.

Acral lentiginous melanoma

Acral lentiginous melanoma (ALM), also called acral melanoma, is a rare melanoma subtype of palms, soles, and nail units, UV-independent, most common in darker-skinned populations, with low mutation burden and poor survival.

Acral peeling skin syndrome

Acral peeling skin syndrome (APSS, peeling skin syndrome 2, OMIM 609796) is a rare autosomal recessive disorder causing painless superficial peeling of hand and foot skin, usually from TGM5 mutations.

Acral persistent papular mucinosis

Acral persistent papular mucinosis (APPM), a rare subtype of localized lichen myxedematosus, causes 2–5 mm flesh-colored papules on the backs of hands, wrists, and distal forearms; benign, skin-limited, female-predominant, no systemic links.

Acral self-healing collodion baby

Acral self-healing collodion baby (ASHCB, ORPHA:281127) is an extremely rare ARCI variant where a collodion membrane at birth is limited to hands and feet, sheds in weeks, and leaves normal skin; linked to TGM1 mutations.

Acrania

Acrania: congenital absence of the fetal cranial vault and overlying skin with exposed brain tissue; first stage of the acrania–exencephaly–anencephaly sequence, lethal, detectable by ultrasound from about 11 weeks.

ACRIN 6657 trial

ACRIN 6657, also known as I-SPY 1, was a National Cancer Institute–funded trial showing breast MRI predicted response to neoadjuvant chemotherapy in locally advanced breast cancer better than clinical examination.

Acrisorcin

Acrisorcin (Akrinol) is a topical anti-infective, a 1:1 compound of 4-hexylresorcinol and 9-aminoacridine, CAS 7527-91-5, used as a fungicide and first approved 1982; distinct from acrinol (ethacridine).

Acrivastine

Acrivastine (Benadryl Allergy Relief, Semprex-D) is a short-acting second-generation H1 antihistamine, a triprolidine derivative, taken 8 mg up to three times daily for hay fever and chronic urticaria, with 1.5-hour half-life and low but measurable sedation.

Acro-renal-mandibular syndrome

Acro-renal-mandibular syndrome (OMIM 200980, ORPHA:958) is a rare congenital anomaly disorder combining split hand-split foot malformation, renal agenesis or polycystic kidneys, uterine anomalies, and severe mandibular hypoplasia; inheritance mode remains uncertain.

Acro-renal-ocular syndrome

Acro-renal-ocular syndrome (AROS, OMIM 607323), a rare autosomal dominant SALL4-related disorder with radial ray malformations, renal anomalies, coloboma, and Duane anomaly, allelic to Okihiro syndrome.

Acrocapitofemoral dysplasia

Acrocapitofemoral dysplasia (ACFD) is an ultra-rare autosomal recessive skeletal dysplasia caused by IHH gene variants, marked by short stature, short limbs, and premature growth plate closure.

Acrocardiofacial syndrome

Acrocardiofacial syndrome, also known as CCGE syndrome, is a rare inherited disorder featuring split-hand/split-foot malformation, cleft lip and palate, congenital heart defects, genital anomalies, and intellectual deficit.

Acrocephalopolydactyly

Acrocephalopolydactyly, or Elejalde syndrome (acrocephalopolydactylous dysplasia, OMIM 200995), is an extremely rare lethal autosomal recessive congenital disorder with massive birth weight, edema, polydactyly, and renal dysplasia; fewer than 10 cases reported.

Acrodermatitis continua of Hallopeau

Acrodermatitis continua of Hallopeau (ACH), dermatitis repens, acropustulosis: rare chronic pustular psoriasis variant of the digits with sterile pustules, nail destruction, and osteolysis; IL36RN mutations in 20%; acitretin first-line, biologics second-line.

Acrodysostosis

Acrodysostosis (Arkless-Graham syndrome, Maroteaux-Malamut syndrome): rare autosomal dominant skeletal dysplasia with severe brachydactyly, facial dysostosis, nasal hypoplasia, and hormone resistance, caused by PRKAR1A or PDE4D mutations.

Acrofacial dysostosis, Weyers type

Acrofacial dysostosis, Weyers type (Curry-Hall syndrome, Weyers acrodental dysostosis) is a rare autosomal dominant ciliopathy from EVC2 or EVC variants on 4p16.2, allelic to Ellis-van Creveld syndrome but milder, causing dental anomalies, nail dystrophy, postaxial polydactyly, and mild short stature without heart defects.

Acrofrontofacionasal dysostosis

Acrofrontofacionasal dysostosis, also known as Richieri-Costa-Colletto syndrome, is a rare autosomal recessive disorder present from birth, combining facial and skeletal abnormalities with severe intellectual disability; about 12 patients have been reported since 1985.

Acrogeria

Acrogeria, also called Gottron syndrome, is a rare premature aging syndrome causing atrophy of skin on the hands and feet, with normal survival and internal organs spared.

Acrokeratoelastoidosis of Costa

Acrokeratoelastoidosis of Costa (AKE, PPKP3, OMIM 101850) is a rare autosomal dominant palmoplantar keratoderma first described by Oswaldo Costa in the early 1950s, causing small yellowish firm papules on hand and foot margins with elastic fiber fragmentation (elastorrhexis).

Acrokeratosis verruciformis of Hopf

Acrokeratosis verruciformis of Hopf (AKV, Hopf disease) is a rare autosomal dominant genodermatosis caused by ATP2A2 p.Pro602Leu mutations, allelic to Darier disease, causing flat wart-like papules on the dorsal hands and feet with church-spire histology.

Acromegaly

Acromegaly: chronic disorder from GH hypersecretion by a pituitary adenoma, raising IGF-I and enlarging hands, feet, face; named by Pierre Marie in 1886; treated first with transsphenoidal surgery.

Acromelanosis

Acromelanosis, also called progressive acromelanosis, is a rare skin pigmentation anomaly causing asymptomatic hyperpigmentation on the backs of fingers and toes, sometimes spreading proximally, appearing in newborns or infants, with unknown cause and inheritance.

Acromelic frontonasal dysplasia

Acromelic frontonasal dysplasia (AFND, Toriello syndrome, acromelic frontonasal dysostosis) is a rare autosomal dominant frontonasal dysplasia caused by a recurrent ZSWIM6 p.Arg1163Trp mutation, combining craniofacial, brain, and limb malformations with intellectual disability; about 22 cases reported.

Acromesomelic dysplasia, Grebe type

Acromesomelic dysplasia, Grebe type (Grebe dysplasia, OMIM 200700) is a rare autosomal recessive skeletal dysplasia with severe short-limb dwarfism, limb-only abnormalities, fused or absent carpal/tarsal bones, and ball-shaped fingers, caused by biallelic GDF5 (CDMP1) or rarely BMPR1B variants.

Acromesomelic dysplasia, Hunter-Thompson type

Acromesomelic dysplasia, Hunter-Thompson type, also called AMDH, is a rare autosomal recessive skeletal disorder causing severe short-limb dwarfism with limb abnormalities only, first described in 1976.

Acromesomelic dysplasia, Maroteaux type

Acromesomelic dysplasia, Maroteaux type (AMDM, OMIM 602875) is a rare autosomal recessive skeletal dysplasia caused by biallelic NPR2 loss-of-function, causing severe short stature under 120 cm, shortened middle and distal limb segments, vertebral abnormalities, and normal intelligence.

Acromicric dysplasia

Acromicric dysplasia (ACMICD, OMIM 102370) is a rare autosomal dominant skeletal dysplasia from FBN1 or LTBP3 mutations, causing severe short stature, short hands and feet, stiff joints, and mild facial dysmorphism with normal intelligence.