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1p36-deletion syndrome


ICD-10: Q93.5

ORPHA: 1606

General information

Estimated occurrence
10-20 in 100,000 live births.

Chromosome abnormality caused by a small deletion on the short arm (p) of chromosome 1.

General symptoms

People with 1p36 deletion syndrome have intellectual disabilities and about half have some form of behavioural disorder. Motor development is delayed and many have low muscle tone (muscular hypotonia) and hypermobility of the joints. Epilepsy is very common. Both hearing and vision may be affected. Some individuals with the syndrome have anomalies of the central nervous system, such as hydrocephalus or cerebral atrophy. In new-born babies, closing of the fontanelles is often delayed. Other deformities may occur, the most common being heart defects of different types and severity (approx. 50%), cleft lip and palate (approx. 30%) and abnormalities in the kidneys and urinary tract (approx. 20%).  Other relatively common symptoms are poor function of the thyroid gland, skeletal abnormalities and skin changes. Many infants with this syndrome show stunted growth from birth onwards. There is a gradual improvement in motor skills, communication and behavioural problems as they grow up.


Partial monosomy 1p36 syndrome.

Orofacial/odontological symptoms

Characteristic facial features are associated with the diagnosis. Cleft lip and palate is common. Malocclusion may occur. Oral-motor development is often delayed and the associated muscles are inactive and hypotonic. Difficulties in sucking, eating and drinking and reduced saliva control are common. Speech, language and communication skills are generally affected.

Advice on follow-up and treatment

  • Early contact with dental services for intensified prophylactic care and oral hygiene information is essential.
  • Regular check-ups of dental and jaw development. Orthodontist should be consulted when needed.
  • Training in oral motor skills and extra stimulation in cases of eating disorders, speech difficulties and impaired saliva control may be necessary.
  • Speech, language and communication training is often warranted
  • In cases of cleft lip and palate, a specialist team will be needed for follow up and treatment.
  • When treating medically compromised patients always contact their doctor for medical advice (bleeding problems, heart diseases etc). 
  • Feeding and swallowing difficulties are investigated and treated by a specialist team at the hospital or multidisciplinary treatment centre.


National Board of Health and Welfare

Updated: 2022-01-26 09:19