Each column keeps its native condition scope. Initial features are displayed alphabetically, not ranked by clinical importance. Counts remain separate, and an empty cell does not mean a feature cannot occur.
"},"coverage":{"countRecords":0,"emptyColumnKeys":[],"hpoRelease":"2026-06-23","narrativeSourceChanges":[],"records":5,"sourceGroups":{"omim":2,"orphanet":3,"published":0}},"features":[{"hpoId":"HP:0000365","label":"Hearing loss","primary":false},{"hpoId":"HP:0000962","label":"Hyperkeratosis","primary":false},{"hpoId":"HP:0000972","label":"Palmoplantar hyperkeratosis","primary":false},{"hpoId":"HP:0000982","label":"Palmoplantar keratoderma","primary":false},{"hpoId":"HP:0000407","label":"Sensorineural hearing loss","primary":false}],"ledeHtml":"Palmoplantar keratoderma with deafness is a disorder characterized by skin abnormalities and hearing loss. Affected individuals develop unusually thick skin on the palms of the hands and soles of the feet (palmoplantar keratoderma) beginning in childhood. Hearing loss ranges from mild to profound. It begins in early childhood and gets worse over time. Affected individuals have particular trouble hearing high-pitched sounds.","mondoId":"MONDO:0007852","records":[{"frequencyKind":"reported","key":"074bc6b03e678b41c8e97dc9d7506501312f3df71096dad5e72986a5dd191a6d","raw":{"aspect":"P","body_system":"ear","disease_id":"OMIM:148350","disease_name":"Keratoderma, palmoplantar, with deafness","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0000365","is_excluded":false,"label":"Hearing impairment","onset_id":"HP:0011463","reference":"OMIM:148350","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"629013fce592d2f60c99a052145833af214210cb259e9104308ae32524f255c1","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"OMIM:148350","disease_name":"Keratoderma, palmoplantar, with deafness","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0000972","is_excluded":false,"label":"Palmoplantar hyperkeratosis","onset_id":null,"reference":"OMIM:148350","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"a2bf3f8dbf46d42c7d4c189ff33fd1641f5bc9bd45d897de5e55541dd448607a","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:2202","disease_name":"Palmoplantar keratoderma-deafness syndrome","evidence":"TAS","frequency_raw":"HP:0040281","hpo_id":"HP:0000982","is_excluded":false,"label":"Palmoplantar keratoderma","onset_id":null,"reference":"ORPHA:2202","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"cc118aabbb7ae5dccaa8931f9fc78bd4f91a48bb2c5dc9849a7e861aeb2580c7","raw":{"aspect":"P","body_system":"ear","disease_id":"ORPHA:2202","disease_name":"Palmoplantar keratoderma-deafness syndrome","evidence":"TAS","frequency_raw":"HP:0040281","hpo_id":"HP:0000407","is_excluded":false,"label":"Sensorineural hearing impairment","onset_id":null,"reference":"ORPHA:2202","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"f83f4ea479b9ea128c14df074c7f3ee0822f393506e8e5fce9981422dc2c5524","raw":{"aspect":"P","body_system":"skin","disease_id":"ORPHA:2202","disease_name":"Palmoplantar keratoderma-deafness syndrome","evidence":"TAS","frequency_raw":"HP:0040281","hpo_id":"HP:0000962","is_excluded":false,"label":"Hyperkeratosis","onset_id":null,"reference":"ORPHA:2202","source_release":"2026-06-23"},"sourceGroups":["orphanet"]}],"referenceLabels":{},"references":{"causeHtml":"","identityNote":"MONDO cross-references identify native condition entries. Ancestor membership does not transfer phenotype values between groups.","importantHtml":""},"sections":[{"bodyHtml":"Palmoplantar keratoderma with deafness can be caused by mutations in the GJB2 or MT-TS1 genes.
The GJB2 gene provides instructions for making a protein called gap junction beta 2, more commonly known as connexin 26. Connexin 26 is a member of the connexin protein family. Connexin proteins form channels called gap junctions that permit the transport of nutrients, charged atoms (ions), and signaling molecules between neighboring cells that are in contact with each other. Gap junctions made with connexin 26 transport potassium ions and certain small molecules.
Connexin 26 is found in cells throughout the body, including the inner ear and the skin. In the inner ear, channels made from connexin 26 are found in a snail-shaped structure called the cochlea. These channels may help to maintain the proper level of potassium ions required for the conversion of sound waves to electrical nerve impulses. This conversion is essential for normal hearing. In addition, connexin 26 may be involved in the maturation of certain cells in the cochlea. Connexin 26 also plays a role in the growth, maturation, and stability of the outermost layer of skin (the epidermis).
The GJB2 gene mutations that cause palmoplantar keratoderma with deafness change single protein building blocks (amino acids) in connexin 26. The altered protein probably disrupts the function of normal connexin 26 in cells, and may interfere with the function of other connexin proteins. This disruption could affect skin growth and also impair hearing by disturbing the conversion of sound waves to nerve impulses.
Palmoplantar keratoderma with deafness can also be caused by a mutation in the MT-TS1 gene. This gene provides instructions for making a particular type of RNA, a molecule that is a chemical cousin of DNA. This type of RNA, called transfer RNA (tRNA), helps assemble amino acids into full-length, functioning proteins. The MT-TS1 gene provides instructions for a specific form of tRNA that is designated as tRNASer(UCN). This molecule attaches to a particular amino acid, serine (Ser), and inserts it into the appropriate locations in many different proteins.
The tRNASer(UCN) molecule is present only in cellular structures called mitochondria. These structures convert energy from food into a form that cells can use. Through a process called oxidative phosphorylation, mitochondria use oxygen, simple sugars, and fatty acids to create adenosine triphosphate (ATP), the cell's main energy source. The tRNASer(UCN) molecule is involved in the assembly of proteins that carry out oxidative phosphorylation.
The MT-TS1 gene mutation that causes palmoplantar keratoderma with deafness leads to reduced levels of tRNASer(UCN) to assemble proteins within mitochondria. Reduced production of proteins needed for oxidative phosphorylation may impair the ability of mitochondria to make ATP. Researchers have not determined why the effects of the mutation are limited to cells in the inner ear and the skin in this condition.
","key":"forms","title":"What causes Palmoplantar keratoderma with deafness?"},{"bodyHtml":"The signs and symptoms of this disorder may vary even within the same family, with some individuals developing only skin abnormalities and others developing only hearing loss.
Source: MedlinePlus Genetics
","key":"overview","title":"Condition overview"}],"sharedSources":[],"slug":"palmoplantar-keratoderma-with-deafness","sourceDocuments":[{"name":"Palmoplantar keratoderma with deafness","reviewed":"2012-11","sections":{"causes":{"fetchedAt":"2026-10-20T20:24:03.044536+00:00","label":"Causes","pageSha256":"cacd1252337cc7a7e7c0e93432ca2c61a2e9ae07f24dce61d774e7f357ff3ac3","sourceUrl":"https://medlineplus.gov/genetics/condition/palmoplantar-keratoderma-with-deafness/#causes","status":"available"}},"source_release":"2026-10-01","url":"https://medlineplus.gov/genetics/condition/palmoplantar-keratoderma-with-deafness"}],"sourceNote":"MedlinePlus descriptions and Causes; original HPO annotations.","takeawayHtml":"Cause explanations are from MedlinePlus Genetics. Feature values below retain their original sources and patient groups.","title":"Palmoplantar keratoderma with deafness"},"schemaVersion":1}