Hunter-McAlpine syndrome

Title

Other Names:

Hunter-mcalpine craniosynostosis syndrome; Hunter-mcalpine craniosynostosis; Craniosynostosis, mental deficiency, almond-shaped palpebral fissures, downturned mouth, mild acral-skeletal anomalies, and short stature

Categories:

Congenital and Genetic Diseases; Musculoskeletal Diseases

Summary Summary

Hunter-McAlpine syndrome is a very rare condition characterized by developmental delay, intellectual disability, and small head size (microcephaly). Sometimes the microcephaly results from early closure of the bones in the skull, which is called craniosynostosis. This can cause a misshapen skull and is common in individuals with Hunter-McAlpine syndrome; in fact another name for the condition is Hunter-McAlpine craniosynostosis syndrome.^[1] Hunter-McAlpine syndrome is a genetic condition, meaning that it is caused by changes in the genes. Hunter-McAlpine syndrome is typically diagnosed by genetic testing, and treatment options are focused on managing each individual’s symptoms.

Last updated: 12/15/2016

Symptoms Symptoms

The symptoms of Hunter-McAlpine syndrome include characteristic facial features such as almond-shaped eyes, drooping lower eyelids (ptosis), and a small down-turned mouth. These characteristic facial features cause many children with Hunter-McAlpine syndrome to look like each other. Other symptoms of Hunter-McAlpine syndrome include intellectual disability, developmental delay, microcephaly, and short stature.^[2] Although there is some variability, some children affected by the condition may have delayed puberty or heart defects.^[3] Some affected individuals may also have skeletal changes that affect their fingers and toes.

Last updated: 12/15/2016

The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below.

Signs and Symptoms	Approximate number of patients (when available)
Almond-shaped palpebral fissure	-
Autosomal dominant inheritance	-
Downturned corners of mouth	-
Intellectual disability	-
Narrow mouth	-

Last updated: 9/1/2017

Cause Cause

Hunter-McAlpine syndrome is a genetic condition, meaning that it is caused by changes in a person’s genes. Each cell in our bodies contains 23 pairs of chromosomes for a total of 46 chromosomes in each cell. These chromosomes are packets of genetic information. People affected by Hunter-McAlpine syndrome have a duplication of part of chromosome 5.^[1] This duplication results in extra genetic information and causes the symptoms associated with Hunter-McAlpine syndrome.

Last updated: 12/15/2016

Inheritance Inheritance

Researchers believe that Hunter-McAlpine syndrome is inherited in an autosomal dominant manner. This means that any child of a person with Hunter-McAlpine syndrome has a 50% chance of having the condition themselves. Although the condition is very rare, researchers believe that most cases of Hunter-McAlpine syndrome are caused either by a new genetic change in the affected individual (de novo mutation), or through a parent who has balanced translocation. In this case, the parent has all of the necessary genetic material, but it has been rearranged.^[4] When this rearranged information is passed down to their child, the child can end up with a duplication of chromosome 5.

Last updated: 12/15/2016

Diagnosis Diagnosis

Hunter-McAlpine syndrome is diagnosed by a clinical evaluation and genetic testing. If the genetic test shows that there is a duplication of a specific part of chromosome 5, this confirms the diagnosis of Hunter-McAlpine syndrome.^[1] The doctor may also suggest testing other members of the family. Any siblings might be tested to see if they are affected as well, and parents might be tested to better understand the chance that any future children may be affected with the condition.

Last updated: 12/15/2016

Prognosis Prognosis

There have only been a few dozen reported cases of Hunter-McAlpine syndrome, so the long-term outlook, or prognosis, for people affected by the condition can be difficult to predict. Some individuals with the condition have been reported to live at least into their late 60s.^[2] Although most people with Hunter-McAlpine syndrome typically cannot live alone, with proper support they can live in a group home successfully.

Last updated: 12/15/2016

Do you have updated information on this condition? Let us know.

Research Research

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

ClinicalTrials.gov lists trials that are studying or have studied Hunter-McAlpine syndrome. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Living With Living With

Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Genetics Resources

To find a medical professional who specializes in genetics, you can ask your doctor for a referral or you can search for one yourself. Online directories are provided by GeneTests, the American College of Medical Genetics, and the National Society of Genetic Counselors. If you need additional help, contact a GARD Information Specialist. You can also learn more about genetic consultations from Genetics Home Reference.

Learn More 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.

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 Hunter-McAlpine syndrome. Click on the link to view a sample search on this topic.

News & Events News & Events

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References References

Hunter-McAlpine craniosynostosis. Orphanet; September 2007; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=97340.
Hunter AG, Dupont B, McLaughlin M, Hinton L, Baker E, Adés L, Haan E, and Schwartz CE. The Hunter-McAlpine syndrome results from duplication 5q35-5qter. Clinical Genetics. January 2005; 67(1):53-60. https://www.ncbi.nlm.nih.gov/pubmed/15617549.
Adés LC, Morris LL, Simpson DA, Haan EA. Hunter-McAlpine syndrome: report of a third family. Clinical Dysmorphology. April 1993; 2(2):123-130. https://www.ncbi.nlm.nih.gov/pubmed/8281273.
O’Neill MJF and McKusick VA. Hunter-McAlpine Craniosynostosis Syndrome. Online Mendelian Inheritance in Man; September 19, 2016; http://www.omim.org/entry/601379.