Rare Dermatology News

Disease Profile

Hanhart syndrome

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

<1 / 1 000 000

US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Aglossia adactylia; Hypoglossia-hypodactylia syndrome; Peromelia with micrognathia


Congenital and Genetic Diseases; Mouth Diseases; Musculoskeletal Diseases


Hanhart syndrome is a rare condition that primarily affects the craniofacial region and the limbs (arms and legs). People affected by this condition are often born with a short, incompletely developed tongue; absent or partially missing fingers and/or toes; abnormalities of the arms and/or legs; and an extremely small jaw. The severity of these physical abnormalities varies greatly among affected people, and children with this condition often have some, but not all, of the symptoms. The cause of Hanhart syndrome is not fully understood. Treatment depends on the signs and symptoms present in each person.[1][2][3]


The signs and symptoms of Hanhart syndrome vary, but may include:[3][4][1]

  • Small mouth
  • Short, incompletely developed tongue (hypoglossia)
  • Absent, partially missing, or shortened fingers and/or toes
  • Jaw abnormalities such as micrognathia, retrognathia (receding jaw), or partially missing mandible (lower jaw)
  • High-arched, narrow, or cleft palate
  • Absent or unusually formed arms and/or legs
  • Missing teeth
  • Absence of major salivary glands

Some infants with Hanhart syndrome may be born with paralysis of certain areas of the face. If the tongue and/or mouth are affected, this can worsen feeding difficulties that are already present due to the craniofacial abnormalities listed above.[3]

The severity of the physical abnormalities associated with Hanhart syndrome varies greatly among affected people, and children with this disorder often have some, but not all, of the symptoms.

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Aplasia/Hypoplasia of the tongue
Hypoplasia of the zygomatic bone
Cheekbone underdevelopment
Decreased size of cheekbone
Underdevelopment of cheekbone

[ more ]

Little lower jaw
Small jaw
Small lower jaw

[ more ]

Narrow mouth
Small mouth
Upper limb phocomelia
30%-79% of people have these symptoms
Abnormal fingernail morphology
Abnormal fingernails
Abnormality of the fingernails

[ more ]

Short fingers or toes
Cleft palate
Cleft roof of mouth
Finger syndactyly
Failure of development of between one and six teeth
Short distal phalanx of finger
Short outermost finger bone
Split hand
Claw hand
Claw hand deformities
Claw hands
Claw-hand deformities

[ more ]

Corners of eye widely separated
Wide nasal bridge
Broad nasal bridge
Broad nasal root
Broadened nasal bridge
Increased breadth of bridge of nose
Increased breadth of nasal bridge
Increased width of bridge of nose
Increased width of nasal bridge
Nasal bridge broad
Wide bridge of nose
Widened nasal bridge

[ more ]

5%-29% of people have these symptoms
Abnormal cranial nerve morphology
Anal atresia
Absent anus
Death in infancy
Infantile death
Lethal in infancy

[ more ]

Facial asymmetry
Asymmetry of face
Crooked face
Unsymmetrical face

[ more ]

Feeding difficulties in infancy
High palate
Elevated palate
Increased palatal height

[ more ]

Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific

[ more ]

Jejunal atresia
Neurological speech impairment
Speech disorder
Speech impairment
Speech impediment

[ more ]

Percent of people who have these symptoms is not available through HPO
Failure of development of tongue
Autosomal dominant inheritance
Eye folds
Prominent eye folds

[ more ]

Abnormally small tongue
Underdevelopment of the tongue

[ more ]

Receding chin
Receding lower jaw
Weak chin
Weak jaw

[ more ]

No previous family history


The exact underlying cause of Hanhart syndrome is currently unknown. However, researchers suspect that there may be genetic and/or environmental factors that contribute to the development of the condition. To date, no specific disease-causing genes have been identified. Possible environmental factors including:[2][1]


A diagnosis of Hanhart syndrome is typically made based on the presence of characteristic signs and symptoms. In some cases, the diagnosis may be suspected before birth if concerning features are seen on ultrasound.[3][1]


Because Hanhart syndrome affects many different systems of the body, medical management is often provided by a team of doctors and other healthcare professionals. Treatment for this condition varies because it depends on the signs and symptoms present in each person. For example, limb and/or craniofacial abnormalities may be treated with surgery and/or prostheses. Affected children may also need speech therapy, physical therapy, and/or occupational therapy.[3][2][1]


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Learn more

    These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

    Where to Start

    • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

      In-Depth Information

      • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
      • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
      • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
      • PubMed is a searchable database of medical literature and lists journal articles that discuss Hanhart syndrome. Click on the link to view a sample search on this topic.


        1. Manisha Goyal, Ankur Singh, Pratiksha Singh, and Seema Kapoor. Hypoglossia-Hypodactyly Syndrome with Short Stature A Case Report. J Clin Diagn Res. April 2014; 8(4):SD01–SD02. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4064859/.
        2. Hypoglossia-hypodactyly syndrome. Orphanet. July 2005; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=989.
        3. Hanhart Syndrome. NORD. February 2008; https://www.rarediseases.org/rare-disease-information/rare-diseases/byID/1022/viewAbstract.
        4. HYPOGLOSSIA-HYPODACTYLIA. OMIM. September 2012; https://www.omim.org/entry/103300.
        5. Gathwala G, Singh J, Dalal P, Garg A.. Hypoglossia-hypodactyly syndrome in a newborn. J Craniomaxillofac Surg. March 2011; 39(2):99-101. https://www.ncbi.nlm.nih.gov/pubmed/20673638.

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