Megalencephaly-Capillary Malformation

National Organization for Rare Disorders, Inc.

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It is possible that the main title of the report Megalencephaly-Capillary Malformation is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.


  • macrocephaly-capillary malformation
  • macrocephaly-cutis marmorata telangiectatica congenita
  • MCAP
  • M-CM
  • M-CM syndrome
  • M-CMTC

Disorder Subdivisions

  • None

General Discussion


Megalencephaly-capillary malformation syndrome (MCAP), formerly known as macrocephaly-capillary malformation, is a rare, complex disorder involving the skin, connective tissue, brain and other organs that is usually present at birth. Affected individuals have a disproportionately large head and capillary malformations on the skin of the midline face, trunk and limbs. These capillary malformations often show a lacy or reticulated pattern (resembling a net or web, and are sometimes termed "cutis marmorata"). Most children with MCAP have an enlarged brain (or megalencephaly), in addition to other findings on brain MRI associated with neurologic problems.


Multiple terms have been used in the past for this syndrome. The earliest one was macrocephaly-cutis marmorata telangiectatica congenita (M-CMTC) because the vascular lesions were mistakenly believed to be consistent with CMTC. However, careful examination of the skin in these children revealed that the vascular lesions are not CMTC but rather capillary malformations (described below), and so the syndrome was accurately renamed to "macrocephaly-capillary malformation syndrome" (or M-CM). Recently, the name was modified from this latter term to "megalencephaly-capillary malformation" (or MCAP, in short) because the term "macrocephaly" refers to a large head due various causes, whereas "megalencephaly" is a more specific and accurate term that refers to the truly enlarged brain present in this syndrome.

Supporting Organizations

CMTC-OVM Cutis Marmorata Telangiectatica

Bitterschoten 15
Leusdan, 3831 PC
The Netherlands
Tel: 31334946671

Genetic and Rare Diseases (GARD) Information Center

PO Box 8126
Gaithersburg, MD 20898-8126
Tel: (301)251-4925
Fax: (301)251-4911
Tel: (888)205-2311

M-CM Network

PO Box 97
Chatham, NY 12037

March of Dimes Birth Defects Foundation

1275 Mamaroneck Avenue
White Plains, NY 10605
Tel: (914)997-4488
Fax: (914)997-4763

NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases

Information Clearinghouse
One AMS Circle
Bethesda, MD 20892-3675
Tel: (301)495-4484
Fax: (301)718-6366
Tel: (877)226-4267

National Organization of Vascular Anomalies

PO Box 38216
Greensboro, NC 27438-8216

Nevus Network

PO Box 305
West Salem, NC 44287
Tel: (419)853-4525
Fax: (405)377-3403

The Arc

1825 K Street NW, Suite 1200
Washington, DC 20006
Tel: (202)534-3700
Fax: (202)534-3731
Tel: (800)433-5255

Vascular Birthmarks Foundation

P.O. Box 106
Latham, NY 12110
Tel: (877)823-4646

For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, go to and click on Rare Disease Database under "Rare Disease Information".

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.

It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report

This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P.O. Box 1968, Danbury, CT 06813-1968; phone (203) 744-0100; web site or email

Last Updated:  12/8/1969
Copyright  2011 National Organization for Rare Disorders, Inc.