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1p36 deletion syndrome

AI overview

1p36 deletion syndrome is a congenital genetic disorder characterized by moderate to severe intellectual disability, delayed growth, hypotonia, seizures, limited speech ability, malformations, hearing and vision impairment, and distinct facial features.

Key points
  • It is one of the most common deletion syndromes.
    source quote
    It is one of the most common deletion syndromes.
  • The syndrome affects approximately one in every 5,000 to 10,000 births.
    source quote
    The syndrome is thought to affect one in every 5,000 to 10,000 births.
  • Symptoms may vary depending on the exact location of the chromosomal deletion.
    source quote
    The symptoms may vary, depending on the exact location of the chromosomal deletion.
Symptoms
  • Children exhibit failure to thrive and global delays.
    source quote
    In general, children will exhibit failure to thrive and global delays.
  • Most young children have delayed development of speech and motor skills.
    source quote
    Most young children with 1p36 deletion syndrome have delayed development of speech and motor skills.
  • Speech is severely affected, with many children learning only a few words or having no speech at all.
    source quote
    Speech is severely affected, with many children learning only a few words or having no speech at all.
  • Behavioral problems include temper outbursts, banging or throwing objects, striking people, screaming episodes, and self-injurious behavior.
    source quote
    Behavioral problems are also common, and include temper outbursts, banging or throwing objects, striking people, screaming episodes, and self-injurious behavior (wrist biting, head striking/banging).
  • Most people have some structural abnormality of the brain, and approximately half have epilepsy or other seizures.
    source quote
    Most people with 1p36 deletion syndrome have some structural abnormality of the brain, and approximately half have epilepsy or other seizures.
  • Common visual abnormalities include farsightedness, myopia, and strabismus.
    source quote
    The most common visual abnormalities associated with 1p36 deletion syndrome include farsightedness (hypermetropia), myopia (nearsightedness), and strabismus (cross-eyes).
  • Distinct facial features may include microcephaly, small deep-set eyes, straight eyebrows, broad flat nose, midface hypoplasia, long philtrum, pointed chin, and low-set ears.
    source quote
    These features may include microcephaly (small head), which may be combined with brachycephaly (short head); small, deep-set eyes; straight eyebrows; epicanthal folds; a broad, flat nose and nasal bridge; underdevelopment of the midface (midface hypoplasia); a long philtrum; pointed chin; and abnormally shaped, rotated, low-set ears.
  • Congenital heart defects may include cardiac septal defects, valvular anomalies, and tetralogy of Fallot.
    source quote
    These patients may have congenital heart defects ranging from cardiac septal defects to valvular anomalies and tetralogy of Fallot.
  • Some patients may have LV noncompaction, a form of dilated cardiomyopathy related to deletion of the gene CASZ1.
    source quote
    In particular, some of the patients may have LV noncompaction a form of dilated cardiomyopathy. This form of LV noncompaction cardiomyopathy is thought to be related to the deletion of the gene CASZ1
Diagnosis
  • Diagnosis is usually suspected based on signs and symptoms and confirmed by fluorescence in situ hybridization (FISH).
    source quote
    1p36 deletion syndrome is usually suspected based on the signs and symptoms and confirmed by fluorescence in situ hybridization (FISH).
  • Chromosomal microarray or karyotype analysis may also be used to diagnose 1p36 deletion.
    source quote
    Chromosomal microarray or karyotype analysis may also be used to diagnose 1p36 deletion.
Treatment
  • There is no cure; treatment is focused on relieving symptoms.
    source quote
    There is no cure for 1p36 deletion syndrome, and treatment is focused on relieving symptoms of the disease.
  • Appropriate medication for endocrine and neurologic manifestations, such as anti-seizure medications, is important.
    source quote
    Of particular importance are appropriate medication for endocrine and neurologic manifestations, such as anti-seizure medications.
Red flags
  • Approximately half of patients have epilepsy or other seizures.
    source quote
    approximately half have epilepsy or other seizures
  • Most people have some structural abnormality of the brain.
    source quote
    Most people with 1p36 deletion syndrome have some structural abnormality of the brain
  • Patients may have congenital heart defects including tetralogy of Fallot and LV noncompaction cardiomyopathy.
    source quote
    These patients may have congenital heart defects ranging from cardiac septal defects to valvular anomalies and tetralogy of Fallot.
AI-synthesized from the Wikipedia article “1p36 deletion syndrome”. Not medical advice. Verify source →
1p36 deletion syndrome
Other namesMonosomy 1p36
A toddler showing facial symptoms of the syndrome.
Differential diagnosisRett syndrome, Angelman syndrome, Prader-Willi syndrome
Frequency1 in 5,000 to 1 in 10,000

1p36 deletion syndrome is a congenital genetic disorder characterized by moderate to severe intellectual disability, delayed growth, hypotonia, seizures, limited speech ability, malformations, hearing and vision impairment, and distinct facial features. The symptoms may vary, depending on the exact location of the chromosomal deletion.[1]

The condition is caused by a genetic deletion (loss of a segment of DNA) on the outermost band on the short arm (p) of chromosome 1. It is one of the most common deletion syndromes. The syndrome is thought to affect one in every 5,000 to 10,000 births.[2]

There are a number of signs and symptoms characteristic of monosomy 1p36, but no one individual will display all of the possible features. In general, children will exhibit failure to thrive and global delays.[3]

Developmental and behavioral

Most young children with 1p36 deletion syndrome have delayed development of speech and motor skills. Speech is severely affected, with many children learning only a few words or having no speech at all. Behavioral problems are also common, and include temper outbursts, banging or throwing objects, striking people, screaming episodes, and self-injurious behavior (wrist biting, head striking/banging). A significant proportion of affected people are on the autism spectrum, and many exhibit stereotypy.[3][4]

Neurologic

Most people with 1p36 deletion syndrome have some structural abnormality of the brain, and approximately half have epilepsy or other seizures.[4][3] Almost all children exhibit some degree of hypotonia.[5] Common structural brain abnormalities include agenesis of the corpus callosum, cerebral cortical atrophy, gait abnormalities, and ventriculomegaly. Dysphagia, esophageal reflux, and other feeding difficulties are also common.[3]

Vision

The most common visual abnormalities associated with 1p36 deletion syndrome include farsightedness (hypermetropia), myopia (nearsightedness), and strabismus (cross-eyes). Less common but still recognized are blepharophimosis, cataracts, ocular albinism, optic atrophy, , and optic nerve coloboma.[3]

Distinct facial features

The facial features of 1p36 deletion syndrome have been considered to be characteristic, although few patients have been diagnosed solely on the basis of facial appearance. These features may include microcephaly (small head), which may be combined with brachycephaly (short head); small, deep-set eyes; straight eyebrows; epicanthal folds; a broad, flat nose and nasal bridge; underdevelopment of the midface (midface hypoplasia); a long philtrum; pointed chin; and abnormally shaped, rotated, low-set ears.[4] Infants may have a large anterior fontanelle, or the anterior fontanelle may close late.[6]

Other congenital defects

Skeletal

Short feet, brachydactyly (short fingers), and camptodactyly (permanent flexion of a finger), fifth finger clinodactyly (abnormal curvature) and other skeletal anomalies are sometimes found in conjunction with 1p36 deletion.[5]

Heart

These patients may have congenital heart defects ranging from cardiac septal defects to valvular anomalies and tetralogy of Fallot. In particular, some of the patients may have LV noncompaction a form of dilated cardiomyopathy. This form of LV noncompaction cardiomyopathy is thought to be related to the deletion of the gene CASZ1, this gene in mice leads to ventricular noncompaction.[7][8]

1p36 deletion syndrome is caused by the deletion of the most distal light band of the short arm of chromosome 1.[5]

Human chromosome 1

The breakpoints for 1p36 deletion syndrome have been variable and are most commonly found from 1p36.13 to 1p36.33. 40 percent of all breakpoints occur 3 to 5 million base pairs from the telomere. The size of the deletion ranges from approximately 1.5 million base pairs to greater than 10 million.[9]

Most deletions in chromosome 1p36 are de novo mutations. 20% of patients with 1p36 deletion syndrome inherit the disease from one parent who carries a balanced or symmetrical translocation.[4]

1p36 deletion syndrome is usually suspected based on the signs and symptoms and confirmed by fluorescence in situ hybridization (FISH).[10] Chromosomal microarray or karyotype analysis may also be used to diagnose 1p36 deletion.[5]

There is no cure for 1p36 deletion syndrome, and treatment is focused on relieving symptoms of the disease. Of particular importance are appropriate medication for endocrine and neurologic manifestations, such as anti-seizure medications. Feeding difficulties can be managed with specialized assistive devices or with a gastrostomy (feeding) tube.[3]

1p36 deletion syndrome is the most common terminal deletion syndrome in humans.[6] It occurs in between 1 in 5000 and 1 in 10000 live births.[4] Only 100 cases have been reported between 1981 and 2015.[disputed – discuss][11] The Genetic and Rare Disease Information Center at the National Institutes of Health reports "fewer than 200,000 people in the United States are living with this disorder."[12]

  1. ↑ "Chromosome 1, 1p36 deletion syndrome". WrongDiagnosis. Retrieved 2009-05-25.
  2. ↑ "1p36 deletion syndrome". Orphanet. Retrieved 28 June 2022.
  3. 1 2 3 4 5 6 "Chromosome 1p36 deletion syndrome | Genetic and Rare Diseases Information Center (GARD) – an NCATS Program". rarediseases.info.nih.gov. Archived from the original on 20 September 2018. Retrieved 19 September 2018.
  4. 1 2 3 4 5 "1p36 deletion syndrome". Genetics Home Reference. NIH.
  5. 1 2 3 4 Battaglia, Agatino (June 6, 2013). "1p36 Deletion Syndrome – RETIRED CHAPTER, FOR HISTORICAL REFERENCE ONLY". In Adam, Margaret P.; Ardinger, Holly H.; Pagon, Roberta A.; Wallace, Stephanie E. (eds.). GeneReviews. University of Washington, Seattle. PMID 20301370. Retrieved 2019-02-20.
  6. 1 2 "OMIM Entry - # 607872 - CHROMOSOME 1p36 DELETION SYNDROME". www.omim.org. Retrieved 19 September 2018.
  7. ↑ Jordan, Valerie K; Zaveri, Hitisha P; Scott, Daryl A (August 27, 2015). "1p36 deletion syndrome: an update". The Application of Clinical Genetics. 8. Informa UK Limited: 189–200. doi:10.2147/TACG.S65698. ISSN 1178-704X. PMC 4555966. PMID 26345236.
  8. ↑ Pierpont, Mary Ella; Brueckner, Martina; Chung, Wendy K.; Garg, Vidu; Lacro, Ronald V.; McGuire, Amy L.; Mital, Seema; Priest, James R.; Pu, William T.; Roberts, Amy; Ware, Stephanie M.; Gelb, Bruce D.; Russell, Mark W. (20 November 2018). "Genetic Basis for Congenital Heart Disease: Revisited". Circulation. 138 (21): e653–e711. doi:10.1161/CIR.0000000000000606. ISSN 0009-7322. PMC 6555769. PMID 30571578.
  9. ↑ Heilstedt, Heidi A.; Ballif, Blake C.; Howard, Leslie A.; Lewis, Richard A.; Stal, Samuel; Kashork, Catherine D.; Bacino, Carlos A.; Shapira, Stuart K.; Shaffer, Lisa G. (2003). "Physical Map of 1p36, Placement of Breakpoints in Monosomy 1p36, and Clinical Characterization of the Syndrome". The American Journal of Human Genetics. 72 (5): 1200–1212. doi:10.1086/375179. PMC 1180272. PMID 12687501.
  10. ↑ "Chromosome 1p36 deletion syndrome". Genetics Testing Reference. Retrieved 2019-02-20.
  11. ↑ Bello, Sabina; Rodríguez-Moreno, Antonio (2016-09-01). "Una revisión actualizada del síndrome de deleción (monosomía) 1p36". Revista Chilena de Pediatría (in Spanish). 87 (5): 411–421. doi:10.1016/j.rchipe.2015.12.004. ISSN 0370-4106. PMID 26875550. An abstract in English language is published: Bello, S.; Rodríguez-Moreno, A. (2016-02-12). "[An updated review of 1p36 deletion (monosomy) syndrome]". Revista Chilena de Pediatria. 87 (5): 411–421. doi:10.1016/j.rchipe.2015.12.004. PMID 26875550.
  12. ↑ Dollemore, Doug (Jul 11, 2023). "Genetic Mutation Could Identify Individuals at Risk of Cardiovascular Death Among Patients with Rare Disease". University of Utah Health. University of Utah. Retrieved 21 May 2025.