Which are the symptoms of Hanhart Syndrome / Hypoglossia-Hypodactyly Syndrome?

Hanhart Syndrome, also known as Hypoglossia-Hypodactyly Syndrome, is an extremely rare genetic disorder that affects the development of the tongue and fingers. It is characterized by the absence or underdevelopment of the tongue (hypoglossia) and the absence or malformation of fingers or toes (hypodactyly).

The symptoms of Hanhart Syndrome can vary in severity and may present differently in each affected individual. The most prominent feature of this syndrome is the hypoglossia, which refers to an abnormally small or absent tongue. The tongue may be partially fused to the floor of the mouth or may be completely absent. This can lead to difficulties in speaking, swallowing, and feeding during infancy.

In addition to the tongue abnormalities, individuals with Hanhart Syndrome may also exhibit hypodactyly, which refers to the underdevelopment or absence of fingers or toes. This can manifest as missing digits, fused digits, or shortened digits. The severity of hypodactyly can vary, ranging from mild finger/toe abnormalities to complete absence of fingers or toes.

Other less common symptoms associated with Hanhart Syndrome may include:

• Cleft palate: Some individuals with Hanhart Syndrome may have a cleft palate, which is a split or opening in the roof of the mouth. This can further contribute to difficulties in feeding, speech, and dental health.


• Facial asymmetry: Facial features may be asymmetrical, with one side of the face appearing different from the other.


• Ear abnormalities: Some individuals may have malformations or hearing loss in one or both ears.


• Delayed speech development: Due to the tongue abnormalities, speech development may be delayed or impaired.


• Dental issues: The absence or underdevelopment of the tongue can lead to dental problems, such as misalignment of teeth and difficulty with oral hygiene.

It is important to note that the symptoms and their severity can vary widely among individuals with Hanhart Syndrome. Some individuals may only have mild tongue or finger abnormalities, while others may have more significant impairments that require medical intervention and support.

Hanhart Syndrome is a congenital condition, meaning it is present from birth. It is caused by mutations in certain genes that are involved in the development of the tongue and limbs during embryonic development. The exact genetic cause of Hanhart Syndrome is not fully understood, and research is ongoing to further elucidate the underlying mechanisms.

Diagnosis of Hanhart Syndrome is typically based on clinical examination, medical history, and imaging studies. Genetic testing may also be performed to confirm the diagnosis and identify the specific genetic mutation involved.

Management of Hanhart Syndrome involves a multidisciplinary approach, with various specialists collaborating to address the specific needs of each individual. Treatment options may include surgical interventions to improve tongue function, speech therapy to aid in speech development, dental care to address oral health issues, and orthopedic interventions for finger/toe abnormalities.

While there is no cure for Hanhart Syndrome, early intervention and ongoing support can greatly improve the quality of life for individuals affected by this rare disorder.