Congenital contractural arachnodactyly (CCA), also known as Beals–Hecht syndrome, is a rare

autosomal dominant In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the Phenotype, effect of a different variant of the same gene on Homologous chromosome, the other copy of the chromosome. The firs ...

congenital A birth defect is an abnormal condition that is present at childbirth, birth, regardless of its cause. Birth defects may result in disability, disabilities that may be physical disability, physical, intellectual disability, intellectual, or dev ...

connective tissue Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesod ...

disorder. As with

Marfan syndrome Marfan syndrome (MFS) is a multi-systemic genetic disorder that affects the connective tissue. Those with the condition tend to be tall and thin, with dolichostenomelia, long arms, legs, Arachnodactyly, fingers, and toes. They also typically ha ...

, people with CCA typically have an arm span that is greater than their height and very long fingers and toes. However, Beals and Hecht discovered in 1972 that, unlike Marfan's, CCA is caused by mutations to the fibrillin-2 (''FBN2'') gene rather than the fibrillin-1 (''FBN1'') gene.

Signs and symptoms

Signs and symptoms of CCA often resemble those of Marfan syndrome, despite the two syndromes' different causes. CCA is characterized by

contracture In pathology, a contracture is a shortening of muscles, tendons, skin, and nearby soft tissues that causes the joints to shorten and become very stiff, preventing normal movement. A contracture is usually permanent, but less commonly can be temp ...

s of varying degrees, mainly involving the large joints, which are present in all affected children at birth. The contractures may be mild and tend to improve over time, but permanently bent fingers and toes (

camptodactyly Camptodactyly is a medical condition that causes one or more Digit (anatomy), digits (fingers or toes) to be permanently bent. It involves fixed Human anatomical terms#Types of movement, flexion deformity of the proximal interphalangeal articulat ...

) are almost always present. In addition to long fingers and toes and a tall, slender body, people with CCA often have ears that appear to be crumpled (a key distinguishing feature from Marfan syndrome), joint stiffness and underdeveloped muscles (muscular

hypoplasia Hypoplasia (; adjective form ''hypoplastic'') is underdevelopment or incomplete development of a tissue or organ.kyphoscoliosis Kyphoscoliosis describes an abnormal curvature of the spine in both the coronal and sagittal planes. It is a combination of kyphosis and scoliosis. This musculoskeletal disorder often leads to other issues in patients, such as under-ventilatio ...

). If kyphoscoliosis is present, it often becomes progressively worse and may require surgery. In some cases, the blood vessel that distributes blood from the heart to the rest of the body (

aorta The aorta ( ; : aortas or aortae) is the main and largest artery in the human body, originating from the Ventricle (heart), left ventricle of the heart, branching upwards immediately after, and extending down to the abdomen, where it splits at ...

) may be abnormally enlarged (

aortic root dilatation Aneurysm of the aortic sinus, also known as the sinus of Valsalva, is a rare abnormality of the aorta, the largest artery in the body. The aorta normally has three small pouches that sit directly above the aortic valve (the sinuses of Valsalva), ...

Causes

Congenital contractural arachnodactyly may be the result of new mutations in the ''FBN2'' gene, located on chromosome 5q23, or it may be inherited from a parent in an

pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Autosomal dominant - en

Diagnosis

CCA may be diagnosed through the physical characteristics associated with the disease of long, slender body and contractures of multiple joints, as well as other symptoms, such as muscular hypoplasia. Molecular genetic tests may be run using

sequence analysis In bioinformatics, sequence analysis is the process of subjecting a DNA, RNA or peptide sequence to any of a wide range of analytical methods to understand its features, function, structure, or evolution. It can be performed on the entire genome ...

or deletion/

duplication Duplication, duplicate, and duplicator may refer to: Biology and genetics * Gene duplication, a process which can result in free mutation * Chromosomal duplication, which can cause Bloom and Rett syndrome * Polyploidy, a phenomenon also known ...

analysis to look for mutations in the ''FBN2'' gene. Prenatal testing may be used for pregnancies with a risk of CCA, such as a parent or sibling with the disease.

Management

Joint contractures are treated using physical therapy to increase mobility and to improve the effects of underdeveloped muscles. Braces and/or surgery may be required to correct kyphoscoliosis. Children born with CCA are usually tested using echocardiograms every two years until the risks of an enlarged aorta (aortic root dilation) have been ruled out. If this is detected, it is managed with standard care for this condition.

Prognosis

Life expectancy may be affected by the disease symptoms present but it is not usually shortened for those with this disease.

References

External links

{{DEFAULTSORT:Beals Syndrome Cytoskeletal defects Systemic connective tissue disorders