The following information may help to address your question:
What is Roberts syndrome?
Roberts syndrome is a genetic disorder characterized by limb and facial abnormalities. Affected individuals are born with abnormalities of all four limbs and typically have shortened arm and leg bones (hypomelia). They may also have
phocomelia (in severe cases); abnormal or missing fingers and toes; joint deformities (
contractures); and numerous facial abnormalities including
cleft lip with or without cleft palate;
micrognathia; ear abnormalities;
hypertelorism; down-slanting
palpebral fissures; small nostrils; and a beaked nose.
Microcephaly,
intellectual disability, and heart, kidney or genital abnormalities may also be present. Infants with a severe form of Roberts syndrome are often stillborn or die shortly after birth, while mildly affected individuals may live into adulthood. It is caused by
mutations in the
ESCO2 gene and is
inherited in an
autosomal recessive pattern.
[1]
Last updated: 2/11/2011
How is Roberts syndrome diagnosed?
The diagnosis of Roberts syndrome is suspected in individuals with the following:
- Prenatal growth delay ranging from mild to severe. Average birth length and weight is typically below the third percentile in most affected infants.
- Limb malformations including bilateral, symmetric tetraphocomelia (phocomelia of all 4 limbs) or hypomelia (underdevelopment of the limbs) caused by mesomelic shortening (shortening of the middle part of the limb). Upper limbs are typically more severely affected than lower limbs. Other limb malformations include oligodactyly with thumb aplasia (lack of formation) or hypoplasia (underdevelopment), syndactyly, clinodactyly, and elbow and knee flexion contractures (inability to fully straighten the arms and legs).
- Craniofacial abnormalities including bilateral cleft lip and/or palate, micrognathia (small jaw), hypertelorism (widely-spaced eyes), exophthalmos (bulging eyes), downslanting palpebral fissures, malar hypoplasia (underdeveloped cheek bones), hypoplastic nasal alae, and ear malformations.
The diagnosis of Roberts syndrome relies on a
cytogenetic blood test of individuals with the above features. Cytogenetic testing would show the characteristic
chromosomal abnormalities that are present in individuals with the condition.
[2]
Last updated: 5/27/2011
Is genetic testing available for Roberts syndrome?
Genetic testing is currently available for Roberts syndrome. GeneTests lists the names of laboratories that are performing genetic testing for Roberts syndrome. To view the contact information for the clinical laboratories conducting testing
click here. To access the contact information for the research laboratories performing genetic testing,
click here.
Please note: Most of the laboratories listed through GeneTests do not accept direct contact from patients and their families; therefore, if you are interested in learning more, you will need to work with a health care provider or a genetics professional.
Last updated: 2/11/2011
What is tetra-amelia syndrome?
Tetra-amelia syndrome is a very rare disorder characterized by the absence of all four limbs. This syndrome can also cause severe malformations of other parts of the body, including the face and head, heart, nervous system, skeleton, and genitalia. The lungs are underdeveloped in many cases, which makes breathing difficult or impossible. Because children with tetra-amelia syndrome have such serious medical problems, most are stillborn or die shortly after birth. The condition has been associated with a
mutation in the
WNT3 gene in one family, and it appears to be inherited in an
autosomal recessive manner.
[3][4] Treatment for those that survive depends upon the presence and severity of the associated symptoms and may require the coordinated efforts of a team of specialists.
[4]
Last updated: 11/8/2016
How is tetra-amelia syndrome diagnosed?
The diagnosis of tetra-amelia syndrome can be established clinically (based on observed features) and is usually made on a routine prenatal
ultrasound. The
WNT3 gene has been associated with tetra-amelia syndrome, but the mutation detection frequency (how often a mutation will be found in an affected individual) is unknown because only a limited number of families have been studied.
[4]
Last updated: 11/8/2016
Is genetic testing available for tetra-amelia syndrome?
The
Genetic Testing Registry (GTR) provides information about the genetic tests for tetra-amelia syndrome. 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.
Last updated: 11/8/2016
How might Roberts syndrome and tetra-amelia syndrome be distinguished?
Other conditions associated with tetra-amelia, including tetra-amelia syndrome, may be considered part of the
differential diagnosis during evaluation for Roberts syndrome when individuals appear to be very severely affected.
[2] There is some overlap of the features present with Robert syndrome and tetra-amelia syndrome; however, tetraphocomelia (
phocomelia involving all 4 limbs) and hypomelia (underdevelopment of limbs) are more commonly seen in individuals with Roberts syndrome (rather than amelia, absence of limbs). Additionally, there are characteristic
cytogenetic abnormalities that are typically present in the
chromosomes of individuals with Roberts syndrome
[2]; cytogenetic testing performed on some of the reported individuals with tetra-amelia syndrome showed normal chromosome results, without the abnormalities typically present with Roberts syndrome.
[4] Individuals that are seeking a diagnosis for themselves should consult with their health care provider or a genetics professional for personalized expert opinion.
Last updated: 2/11/2011
How can I find a genetics professional in my area?
Last updated: 12/6/2017
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GARD Information Specialist
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