Questions about rare diseases?

Disease at a Glance

Summary
Histiocytosis-lymphadenopathy plus syndrome is a group of conditions with overlapping signs and symptoms that affect many parts of the body. This group of disorders includes H syndrome, pigmented hypertrichosis with insulin-dependent diabetes mellitus (PHID), Faisalabad histiocytosis, and familial Rosai-Dorfman disease (also known as familial sinus histiocytosis with massive lymphadenopathy or FSHML). These conditions were once thought to be distinct disorders; however, because of the overlapping features and shared genetic cause, they are now considered to be part of the same disease spectrum. While some affected individuals have signs and symptoms characteristic of one of these conditions, others have a range of features from two or more of the conditions. The pattern of signs and symptoms can vary, even within the same family. All of the conditions in the spectrum are characterized by histiocytosis, which is an overgrowth of immune system cells called histiocytes. These cells abnormally accumulate in one or more tissues in the body, which can lead to organ or tissue damage. The lymph nodes are commonly affected, leading to swelling of the lymph nodes (lymphadenopathy). Other areas of cell accumulation can include skin, kidneys, brain and spinal cord (central nervous system), or digestive tract. The spectrum is known as histiocytosis-lymphadenoapthy plus syndrome because the disorders that make up the spectrum can have additional signs and symptoms. H syndrome is named for the collection of symptoms - all starting with the letter H - that are commonly present. These include hyperpigmented skin lesions with excessive hair growth (hypertrichosis) and histiocyte accumulation, enlargement of the liver or liver and spleen (hepatomegaly or hepatosplenomegaly), heart abnormalities, hearing loss, reduced amounts of hormones that direct sexual development (hypogonadism), and short stature (reduced height). In some cases, hyperglycemia/diabetes mellitus may also be present. PHID is characterized by patches of hyperpigmented skin with hypertrichosis and the development of type 1 diabetes during childhood. Faisalabad histiocytosis is characterized by lymphadenopathy and swelling of the eyelids due to the accumulation of histiocytes. Affected individuals may also have joint deformities (contractures) in their fingers or toes, and hearing loss. Familial Rosai-Dorfman disease is characterized by lymphadenopathy, most often in the neck. Histiocytes can also accumulate in other parts of the body. Histiocytosis-lymphadenopathy plus syndrome is caused by genetic changes in the SLC29A3 gene. The condition is inherited in an autosomal recessive pattern.
Summary
Histiocytosis-lymphadenopathy plus syndrome is a group of conditions with overlapping signs and symptoms that affect many parts of the body. This group of disorders includes H syndrome, pigmented hypertrichosis with insulin-dependent diabetes mellitus (PHID), Faisalabad histiocytosis, and familial Rosai-Dorfman disease (also known as familial sinus histiocytosis with massive lymphadenopathy or FSHML). These conditions were once thought to be distinct disorders; however, because of the overlapping features and shared genetic cause, they are now considered to be part of the same disease spectrum. While some affected individuals have signs and symptoms characteristic of one of these conditions, others have a range of features from two or more of the conditions. The pattern of signs and symptoms can vary, even within the same family. All of the conditions in the spectrum are characterized by histiocytosis, which is an overgrowth of immune system cells called histiocytes. These cells abnormally accumulate in one or more tissues in the body, which can lead to organ or tissue damage. The lymph nodes are commonly affected, leading to swelling of the lymph nodes (lymphadenopathy). Other areas of cell accumulation can include skin, kidneys, brain and spinal cord (central nervous system), or digestive tract. The spectrum is known as histiocytosis-lymphadenoapthy plus syndrome because the disorders that make up the spectrum can have additional signs and symptoms. H syndrome is named for the collection of symptoms - all starting with the letter H - that are commonly present. These include hyperpigmented skin lesions with excessive hair growth (hypertrichosis) and histiocyte accumulation, enlargement of the liver or liver and spleen (hepatomegaly or hepatosplenomegaly), heart abnormalities, hearing loss, reduced amounts of hormones that direct sexual development (hypogonadism), and short stature (reduced height). In some cases, hyperglycemia/diabetes mellitus may also be present. PHID is characterized by patches of hyperpigmented skin with hypertrichosis and the development of type 1 diabetes during childhood. Faisalabad histiocytosis is characterized by lymphadenopathy and swelling of the eyelids due to the accumulation of histiocytes. Affected individuals may also have joint deformities (contractures) in their fingers or toes, and hearing loss. Familial Rosai-Dorfman disease is characterized by lymphadenopathy, most often in the neck. Histiocytes can also accumulate in other parts of the body. Histiocytosis-lymphadenopathy plus syndrome is caused by genetic changes in the SLC29A3 gene. The condition is inherited in an autosomal recessive pattern.
Read More
Resource(s) for Medical Professionals and Scientists on This Disease:

About H syndrome

Many rare diseases have limited information. Currently, GARD aims to provide the following information for this disease:

  • Population Estimate:Fewer than 1,000 people in the U.S. have thisdisease.
  • Symptoms:May start to appear as a Child.
  • Cause:This disease is caused by a change in the genetic material (DNA).
  • Organizations:Patient organizations are available to help find a specialist, or advocacy and support for this specific disease.
  • Categories:Birth DefectsGenetic DiseasesEndocrine DiseasesSkin Diseases
When Do Symptoms of H syndrome Begin?
Symptoms of this disease may start to appear as a Child.

The age symptoms may begin to appear differs between diseases. Symptoms may begin in a single age range, or during several age ranges. The symptoms of some diseases may begin at any age. Knowing when symptoms may have appeared can help medical providers find the correct diagnosis.
Prenatal
Before Birth
Newborn
Birth-4 weeks
Infant
1-23 months
Child Selected
2-11 years
Adolescent
12-18 years
Adult
19-65 years
Older Adult
65+ years
Symptoms may start to appear as a Child.

Symptoms

The types of symptoms experienced, and their intensity, may vary among people with this disease. Your experience may be different from others. Consult your health care team for more information.

The following describes the symptom(s) associated with this disease along with the corresponding body system(s), description, synonyms, and frequency (Note: Not all possible symptoms may be listed):

46 Symptoms

46 Symptoms

46 Symptoms

Body Systems

Symptoms related to this disease may affect different systems of the body. Use the 'Filter and Sort' function to learn more about which body system(s) are affected by this disease and their associated symptom(s).

Causes

What Causes This Disease?

Genetic Mutations

Can This Disease Be Passed Down From Parent to Child?

Autosomal Recessive

Find Your Community

How Can Patient Organizations Help?

Patient organizations can help patients and families connect. They build public awareness of the disease and are a driving force behind research to improve patients' lives. They may offer online and in-person resources to help people live well with their disease. Many collaborate with medical experts and researchers.

Services of patient organizations differ, but may include:

  • Ways to connect to others and share personal stories
  • Easy-to-read information
  • Up-to-date treatment and research information
  • Patient registries
  • Lists of specialists or specialty centers
  • Financial aid and travel resources

Please note: GARD provides organizations for informational purposes only and not as an endorsement of their services. Please contact an organization directly if you have questions about the information or resources it provides.

View GARD's criteria for including patient organizations, which can be found under the FAQs on our About page. Request an update or to have your organization added to GARD

Patient Organizations

7 Organizations

Organization Name

Who They Serve

Helpful Links

Country

People With

H syndrome

Country

United States

People With

H syndrome

Helpful Links
Country

Canada

People With

Skin diseases

Helpful Links
Country

United States

People With

Rare Diseases

Helpful Links
Country

United States

People With

Rare Diseases

Helpful Links
Country

United States

People With

Rare Diseases

Helpful Links
Country

United States

People With

Rare Diseases

Helpful Links
Country

United States

Participating in Clinical Studies

Clinical studies are part of clinical research and play an important role in medical advances, including for rare diseases. Through clinical studies, researchers may ultimately uncover better ways to treat, prevent, diagnose, and understand human diseases.

What Are Clinical Studies?

  1. Clinical trials determine if a new test or treatment for a disease is effective and safe by comparing groups receiving different tests/treatments.
  2. Observational studies involve recording changes over time among a specific group of people in their natural settings.
Learn more about clinical trials from this U.S. Food & Drug Administration webpage.

Why Participate in Clinical Studies?

What if There Are No Available Clinical Studies?

Join the All of Us Research Program!

What Are Clinical Studies?

Clinical studies are medical research involving people as participants. There are two main types of clinical studies:
  1. Clinical trials determine if a new test or treatment for a disease is effective and safe by comparing groups receiving different tests/treatments.
  2. Observational studies involve recording changes over time among a specific group of people in their natural settings.
Learn more about clinical trials from this U.S. Food & Drug Administration webpage.
Read More

Why Participate in Clinical Studies?

People participate in clinical trials for many reasons. People with a disease may participate to receive the newest possible treatment and additional care from clinical study staff as well as to help others living with the same or similar disease. Healthy volunteers may participate to help others and to contribute to moving science forward.

To find the right clinical study we recommend you consult your doctors, other trusted medical professionals, and patient organizations. Additionally, you can use ClinicalTrials.gov to search for clinical studies by disease, terms, or location.
Read More

What if There Are No Available Clinical Studies?

Join the All of Us Research Program!

ClinicalTrials.gov, an affiliate of NIH, provides current information on clinical research studies in the United States and abroad. Talk to a trusted doctor before choosing to participate in any clinical study. We recommend checking this site often and searching for studies with related terms/synonyms to improve results.
Contact a GARD Information Specialist if you need help finding more information on this rare disease or available clinical studies. Please note that GARD cannot enroll individuals in clinical studies. 
Available toll-free Monday through Friday from 12 pm to 6 pm Eastern Time
(Except: Federal Holidays)
Use the contact form to send your questions to a GARD Information Specialist.

Please allow 2 to 10 business days for us to respond.
ClinicalTrials.gov, an affiliate of NIH, provides current information on clinical research studies in the United States and abroad. Talk to a trusted doctor before choosing to participate in any clinical study. We recommend checking this site often and searching for studies with related terms/synonyms to improve results.
Contact a GARD Information Specialist if you need help finding more information on this rare disease or available clinical studies. Please note that GARD cannot enroll individuals in clinical studies. 
Available toll-free Monday through Friday from 12 pm to 6 pm Eastern Time
(Except: Federal Holidays)
Use the contact form to send your questions to a GARD Information Specialist.

Please allow 2 to 10 business days for us to respond.
Getting a Diagnosis

Take steps toward getting a diagnosis by working with your doctor, finding the right specialists, and coordinating medical care.

Last Updated: September 2024