Chromosome 3p- syndrome

Title

Other Names:

Del(3p) syndrome; Chromosome 3, monosomy 3p25; Deletion 3p25; Del(3p) syndrome; Chromosome 3, monosomy 3p25; Deletion 3p25; Chromosome 3pter-p25 Deletion Syndrome; Telomeric monosomy 3p; Distal 3p deletion; 3p- syndrome; Distal monosomy 3p; Monosomy 3pter See More

Categories:

Chromosome Disorders; Congenital and Genetic Diseases; Nervous System Diseases

Summary Summary

Chromosome 3p- syndrome is a rare chromosome abnormality that occurs when there is a missing copy of the genetic material located towards the end of the short arm (p) of chromosome 3. The severity of the condition and the signs and symptoms depend on the exact size and location of the deletion and which genes are involved. Some affected people appear to have no features or mild features, while others are more severely affected. Common symptoms shared by many people with this deletion include poor growth, developmental delay, intellectual disability, distinctive facial features, autism spectrum disorder, an unusually small head (microcephaly), and poor muscle tone (hypotonia). Most cases are not inherited, but people can pass the deletion on to their children. Treatment is based on the signs and symptoms present in each person.^[1]^[2]^[3]

Last updated: 5/10/2015

Symptoms Symptoms

The signs and symptoms of chromosome 3p- syndrome and the severity of the condition depend on the exact size and location of the deletion and which genes are involved. Some affected people appear to have no features or mild features, while others are more severely affected.

Common symptoms shared by many people with this condition include:^[1]^[2]

Growth problems both before and after birth
Feeding difficulties
Developmental delay
Poor muscle tone (hypotonia)
Intellectual disability
Ptosis
Distinctive facial features
Microcephaly and/or unusual head shape
Autism spectrum disorder

Other features that may be seen include cleft palate; extra fingers and/or toes; gastrointestinal abnormalities; seizures; hearing impairment; kidney problems; and/or congenital heart defects.^[1]^[2]

To read more about some of the signs and symptoms reported in people with 3p deletion syndrome, you can read Unique's disorder guide entitled '3p25 deletions.' The information in this guide is drawn partly from the
published medical literature, and partly from Unique's database of members with a 3p deletion.

Last updated: 5/10/2015

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)
Cognitive impairment	Very frequent (present in 80%-99% of cases)
Hypertelorism	Very frequent (present in 80%-99% of cases)
Long philtrum	Very frequent (present in 80%-99% of cases)
Micrognathia	Very frequent (present in 80%-99% of cases)
Ptosis	Very frequent (present in 80%-99% of cases)
Telecanthus	Very frequent (present in 80%-99% of cases)
Brachycephaly	Frequent (present in 30%-79% of cases)
Cryptorchidism	Frequent (present in 30%-79% of cases)
Downturned corners of mouth	Frequent (present in 30%-79% of cases)
Epicanthus	Frequent (present in 30%-79% of cases)
Hearing impairment	Frequent (present in 30%-79% of cases)
High palate	Frequent (present in 30%-79% of cases)
Intrauterine growth retardation	Frequent (present in 30%-79% of cases)
Low-set, posteriorly rotated ears	Frequent (present in 30%-79% of cases)
Microcephaly	Frequent (present in 30%-79% of cases)
Muscular hypotonia	Frequent (present in 30%-79% of cases)
Postaxial hand polydactyly	Frequent (present in 30%-79% of cases)
Abnormal renal morphology	Occasional (present in 5%-29% of cases)
Abnormal vestibulo-ocular reflex	Occasional (present in 5%-29% of cases)
Anteverted nares	Occasional (present in 5%-29% of cases)
Blepharophimosis	Occasional (present in 5%-29% of cases)
Clinodactyly of the 5th finger	Occasional (present in 5%-29% of cases)
Inguinal hernia	Occasional (present in 5%-29% of cases)
Macular hypoplasia	Occasional (present in 5%-29% of cases)
Preauricular pit	Occasional (present in 5%-29% of cases)
Prominent nasal bridge	Occasional (present in 5%-29% of cases)
Sacral dimple	Occasional (present in 5%-29% of cases)
Seizures	Occasional (present in 5%-29% of cases)
Short neck	Occasional (present in 5%-29% of cases)
Spasticity	Occasional (present in 5%-29% of cases)
Thin vermilion border	Occasional (present in 5%-29% of cases)
Triangular face	Occasional (present in 5%-29% of cases)
Umbilical hernia	Occasional (present in 5%-29% of cases)
Ventriculomegaly	Occasional (present in 5%-29% of cases)
Autosomal dominant inheritance	-
Feeding difficulties	-
Flat occiput	-
Low-set ears	-
Periorbital fullness	-
Postaxial polydactyly	-
Postnatal growth retardation	-
Prominent metopic ridge	-
Retrognathia	-
Synophrys	-
Trigonocephaly	-
Upslanted palpebral fissure	-

Last updated: 9/1/2017

Cause Cause

In most people with chromosome 3p- syndrome, the deletion occurs as a new mutation (called a de novo mutation) and is not inherited from a parent. De novo mutations are due to a random error that occurs during the formation of egg or sperm cells, or shortly after conception. In a few cases, the deletion is inherited from a parent.^[2]

Last updated: 5/10/2015

Inheritance Inheritance

In most cases, chromosome 3p- syndrome occurs for the first time in the affected person (de novo mutation). However, the deletion is rarely inherited from a parent. In these cases, the deletion is passed down in an autosomal dominant manner. This means that a person with chromosome 3p- syndrome has a 50% chance with each pregnancy of passing the condition on to his or her child.

In theory, it is possible for a parent to not have the deletion in their chromosomes on a blood test, but have the deletion in some of their egg or sperm cells only. This phenomenon is called germline mosaicism. In these rare cases, it would be possible to have another child with the deletion. To our knowledge, this has not been reported with chromosome 3p- syndrome.^[4]

People interested in learning more about genetic risks to themselves or family members should speak with a genetics professional.

Last updated: 5/10/2015

Diagnosis Diagnosis

There are several different specialized tests that can be used to diagnose a chromosome 3p- syndrome. These include:^[5]^[2]

Karyotype - a karyotype is a laboratory test that produces an image of a person's chromosomes. This test can be used to diagnose large deletions.
FISH - a laboratory technique that is used to detect and locate a specific DNA sequence on a chromosome. During FISH, a chromosome is exposed to a small DNA sequence called a probe that has a fluorescent molecule attached to it. The probe sequence binds to its corresponding sequence on the chromosome. This test can be used in combination with karyotyping for deletions that are too small to be seen on karyotype, alone. However, FISH is only useful if the person ordering the test suspects there is a duplication of a specific region of 3p.
Array CGH - a technology that detects deletions that are too small to be seen on karyotype.

Last updated: 5/10/2015

Testing Resources

The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

Treatment Treatment

Because chromosome 3p- syndrome affects many different systems of the body, medical management is often provided by a team of doctors and other healthcare professionals. Treatment for this deletion varies based on the signs and symptoms present in each person. For example, children with delayed motor milestones (i.e. walking) and/or muscle problems may be referred for physical or occupational therapy. Severe feeding difficulties may be treated temporarily with a nasogastric tube or a gastrostomy tube to ensure that a baby or child gets enough nutrients. Certain medications may be prescribed to treat seizures. Special education services are often necessary for children with intellectual disability. Surgery may be required to treat certain physical abnormalities such as cleft palate or congenital heart defects, if present.^[2]^[3]

Please speak to your healthcare provider if you have any questions about your personal medical management plan.

Last updated: 5/10/2015

Prognosis Prognosis

The long-term outlook (prognosis) for people with chromosome 3p- syndrome varies from person to person. The severity of the condition and the associated signs and symptoms largely depend on the size and location of the deletion and the genes involved.^[2]

Last updated: 5/10/2015

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

Organizations Organizations

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

Chromosome Disorder Outreach
PO Box 724
Boca Raton, FL 33429
Telephone: 561-395-4252
E-mail: info@chromodisorder.org
Website: http://www.chromodisorder.org
Unique – Rare Chromosome Disorder Support Group
G1, The Stables
Station Road West
Surrey
RH8 9EE
United Kingdom
Telephone: +44 (0)1883 723356
E-mail: info@rarechromo.org
Website: http://www.rarechromo.org

Do you know of an organization? Send us your suggestions.

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.

Where to Start

Genetics Home Reference (GHR) contains information on Chromosome 3p- syndrome. This website is maintained by the National Library of Medicine.
The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.
Unique is a source of information and support for families and individuals affected by rare chromosome disorders. Click on the link to view information about Chromosome 3p- syndrome.

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 Chromosome 3p- syndrome. Click on the link to view a sample search on this topic.

News & Events News & Events

News

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The following diseases are related to Chromosome 3p- syndrome. If you have a question about any of these diseases, you can contact GARD.

Chromosome 3p deletion

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My great niece was just diagnosed with this 2 days ago. She is 10 months old and underwent blood tests 7 months ago. The doctors failed to tell my niece the results until two days ago. Is there any information about this disorder that we can find? My searches are turning up very minimal data. See answer
My daughter has a 3p25 deletion. How rare is this disorder? What are the chances that she will learn to walk or talk? See answer

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