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Diseases

Genetic and Rare Diseases Information Center (GARD)

Milroy disease


Other Names for this Disease
  • Congenital hereditary lymphedema
  • Early onset lymphedema
  • Hereditary lymphedema
  • Hereditary lymphedema 1
  • Hereditary lymphedema type I
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.

Your Question

I have two older brothers with Milroy disease. I do not exhibit any signs or symptoms of the condition. I am currently pregnant and was under the impression that since I do not show the signs of Milroy disease that my offspring would not be at risk for this disorder. Am I correct in my understanding that an autosomal dominant trait must be present in order to be passed on to offspring? 

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

Are my offspring at risk for Milroy disease even if I don't have any signs of the condition myself?

When a genetic disorder is diagnosed in a family, family members often want to know the likelihood that they or their children will develop the condition. This can be difficult to predict in some cases because many factors influence a person’s chances of developing a genetic condition. One important factor is how the condition is inherited. Milroy disease is inherited in an autosomal dominant manner. Most individuals diagnosed with Milroy disease have an affected parent. However, some people with a disease-causing mutation never develop any health problems (reduced penetrance) or may experience only mild symptoms (variable expressivity) of the disorder.[1]

Estimating the chance of developing or passing on a genetic disorder can be complex. Genetics professionals can help people understand these chances and help them make informed decisions about their health.  
Last updated: 7/29/2011

How is Milroy disease inherited?

Milroy disease is inherited in an autosomal dominant manner. This means that having one changed (mutated) copy of the responsible gene in each cell is enough to cause symptoms of the condition. When a person with an autosomal dominant condition has children, each child has a 50% (1 in 2) chance to inherit the mutated copy of the gene.

Most people with Milroy disease have an affected parent, but some cases are due to new mutations that occur for the first time in the affected person. About 10-15% of people with a mutation in the responsible gene do not develop features of the condition. This phenomenon is called reduced penetrance.[2]
Last updated: 1/29/2015

What is reduced penetrance?

Penetrance refers to the proportion of people with a particular genetic change (such as a mutation in a specific gene) who exhibit signs and symptoms of a genetic disorder. If some people with the mutation do not develop features of the disorder, the condition is said to have reduced (or incomplete) penetrance. Reduced penetrance probably results from a combination of genetic, environmental, and lifestyle factors, many of which are unknown. This phenomenon can make it challenging for genetics professionals to interpret a person’s family medical history and predict the risk of passing a genetic condition to future generations.[1]
Last updated: 7/29/2011

What is variable expression?

Although some genetic disorders exhibit little variation, most have signs and symptoms that differ among affected individuals. Variable expressivity refers to the range of signs and symptoms that can occur in different people with the same genetic condition. As with reduced penetrance, variable expressivity is probably caused by a combination of genetic, environmental, and lifestyle factors, most of which have not been identified. If a genetic condition has highly variable signs and symptoms, it may be challenging to diagnose.[1]
Last updated: 7/29/2011

Is genetic testing available for Milroy disease?

Yes. The Genetic Testing Registry (GTR) provides information about the labs that offer genetic testing for Milroy disease. The intended audience for the GTR is health care providers and researchers. People with questions about genetic testing should speak with a health care provider or genetics professional.

If a mutation in the responsible gene has been identified in a family, genetic testing for at-risk relatives may identify those who may benefit from treatment early in the disease course. Prenatal testing for pregnancies at increased risk may also be available.[2]
Last updated: 1/29/2015

How can I find a genetics professional in my area?

Genetics clinics are a source of information for individuals and families regarding genetic conditions, treatment, inheritance, and genetic risks to other family members. More information about genetic consultations is available from Genetics Home Reference. To find a genetics clinic, we recommend that you contact your primary healthcare provider for a referral.

The following online resources can help you find a genetics professional in your community:

Last updated: 11/27/2014

References
Other Names for this Disease
  • Congenital hereditary lymphedema
  • Early onset lymphedema
  • Hereditary lymphedema
  • Hereditary lymphedema 1
  • Hereditary lymphedema type I
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.