Gardner–Diamond syndrome is a very rare skin disorder in which painful, red and swollen patches suddenly appear and then turn into deep purple bruises ...

Autoerythrocyte Sensitization Syndrome is a rare condition where people develop painful, tender skin swellings that turn into dark bruises (ecchymoses) within ...

Autism-facial port-wine stain syndrome describes a very rare pattern seen in a handful of children: a unilateral facial port-wine stain (a flat, ...

Intellectual developmental disorder due to AUTS2 deficiency is a rare genetic neurodevelopmental condition. It happens when one copy of the AUTS2 gene does not ...

Autism spectrum disorder due to AUTS2 deficiency is a rare, genetic neurodevelopmental condition caused by harmful changes (variants) in the AUTS2 gene. The ...

Autism spectrum disorder – epilepsy – arthrogryposis syndrome is a rare genetic condition. Children are born with tight or stiff joints (arthrogryposis), and ...

Auriculoosteodysplasia is a very rare inherited condition. It mainly affects the bones and the outer part of the ears. People with this condition have changes ...

Question mark ear syndrome describes a rare pattern of ear and jaw development differences present at birth. The most visible sign is a special ear shape that ...

Auriculocondylar syndrome is a genetic condition that affects how the ears and lower jaw form before birth. A typical sign is the “question-mark ear”—a split ...

Auricular Abnormalities–Cleft Lip (with or without Cleft Palate)–Ocular Abnormalities Syndrome is a very rare birth condition in which a child has three main ...

Auditory neuropathy–optic atrophy syndrome (ANOA) is a rare neurological condition in which the hearing nerve pathway does not transmit sound signals properly ...

Auditory dys-synchrony (auditory neuropathy spectrum disorder, ANSD) is a hearing disorder in which sound enters the ear normally and the outer hair cells of ...

Auditory neuropathy is a hearing disorder where the inner ear (the cochlea) often “hears” sound normally, but the message does not travel correctly along the ...

Okamoto syndrome is a very rare genetic condition that affects how a child grows and develops. It is usually caused by a change (variant) in a single gene ...

Neurodevelopmental disorder–craniofacial dysmorphism–cardiac defect–hip dysplasia syndrome is a very rare, genetic, multi-system condition. Most babies show ...

Spondylolysis means there is a small break (a “stress fracture”) or a thinning/defect in a narrow bridge of bone at the back of a vertebra called the pars ...

Au–Kline syndrome (AKS) is a very rare, genetic condition that affects many body systems. Most people with AKS have weak muscle tone in infancy (hypotonia), ...

Atypical Progeroid Syndrome (APS) is a very rare genetic condition in which a person shows signs that resemble early aging (progeroid features) but does not ...

Atypical Werner syndrome (AWS) is a group of rare “progeroid” conditions that look like classic Werner syndrome—early graying, thin tight skin, short stature, ...

Atypical Rett syndrome (sometimes called a “variant” of Rett) is a neurodevelopmental condition in which a child—most often a girl—shows several hallmark Rett ...