Adducted thumb and clubfoot syndrome

December 31, 2014

Synonyms

Overview

Adducted thumb and clubfoot syndrome is an autosomal recessive connective tissue disorder characterized by congenital malformations, contractures of thumbs and feet, a typical facial appearance, and normal cognitive development. It is also characterized by a thumb abnormality as well as mental retardation, foot defects and other anomalies. This condition is caused by mutations in the CHST14 gene.

Symptoms

Adducted thumb-clubfoot syndrome is characterized by

Typical facial appearance
Slight build
Thin and translucent skin
Severely adducted thumbs
Arachnodactyly
Clubfeet
Joint instability
Facial clefting
Coagulopathy
Heart
Kidney
Intestinal defects
Severe psychomotor and developmental delay and decreased muscle tone may also be present during infancy
Cognitive development during childhood is normal

Some of the symptoms of Adducted thumb and clubfoot syndrome include

Long thin fingers
Clasp thumb
Downturned mouth
Large fontanelle
Abnormality of the fontanelles or cranial sutures
Adducted thumb
Arachnodactyly
Cognitive impairment
Cryptorchidism
Low-set, posteriorly rotated ears
Talipes
Long thin fingers
Large fontanelle
Mental retardation
Anterior eye chamber abnormalities
Broad head
Prominent forehead
Telecanthus
Downslanting palpebral fissures

Causes

A combination of genetic and environmental factors in utero appears to cause clubfoot. Heredity is a definite factor in some cases, although the mechanism of transmission is undetermined. In children without a family history of clubfoot, this anomaly seems linked to arrested development during the 9th and 10th weeks of embryonic life, when the feet are formed. Researchers also suspect muscle abnormalities, leading to variations in length and tendon insertions, as possible causes of clubfoot. Clubfoot, which has an incidence of approximately 1 per 1,000 live births, usually occurs bilaterally and is twice as common in boys. It may be associated with other birth defects, such as myelomeningocele, spina bifida, and arthrogryposis.

Diagnosis

A diagnosis can be made by an evaluation of medical history and clinical observation. The Brighton criteria are widely used to assess the degree of joint hypermobility. DNA and biochemical studies can help identify affected individuals. Diagnostic tests include collagen gene mutation testing, collagen typing via skin biopsy, echocardiogram, and lysyl hydroxylase or oxidase activity. However, these tests are not able to confirm all cases, especially in instances of an unmapped mutation, so clinical evaluation by a geneticist remains essential. If there are multiple affected individuals in a family, it may be possible to perform prenatal diagnosis using a DNA information technique known as a linkage study.

Differential diagnosis:
There are several disorders that share some characteristics with Ehlers–Danlos syndrome. For example, in cutis laxa the skin is loose, hanging, and wrinkled. In EDS, the skin can be pulled away from the body but is elastic and returns to normal when let go. In Marfan syndrome, the joints are very mobile and similar cardiovascular complications occur. People with EDS tend to have a "Marfanoid" appearance (e.g., tall, skinny, long arms and legs, "spidery" fingers). However, physical appearance and features in several types of Ehlers-Danlos Syndrome also have characteristics including short stature, large eyes, and the appearance of a small mouth and chin, due to a small palate. The palate can have a high arch, causing dental crowding. Blood vessels can sometimes be easily seen through translucent skin, especially on the chest. In the past, Menkes disease, a copper metabolism disorder, was thought to be a form of Ehlers–Danlos syndrome. It is not uncommon for patients to be misdiagnosed with fibromyalgia, bleeding disorders or other disorders that can mimic EDS symptoms before a correct diagnosis is made. Because of these similar disorders and complications that can arise from an unmonitored case of EDS, a correct diagnosis is very important. Pseudoxanthoma elasticum (PXE) is worth consideration in diagnosing a patient.

Prognosis

The outlook for individuals with EDS depends on the type of EDS they have. Symptoms vary in severity, even within one sub-type, and the frequency of complications changes individually. Some people have negligible symptoms while others are severely restricted in their daily life. Extreme joint instability, chronic musculoskeletal pain, degenerative joint disease, frequent injuries, and spinal deformities may limit mobility. Severe spinal deformities may affect breathing. In the case of extreme joint instability, dislocations may result from simple tasks such as rolling over in bed or turning a doorknob. Secondary conditions such as autonomic dysfunction or cardiovascular problems, occurring in any type, can affect prognosis and quality of life. Severe mobility-related disability is seen more often in Hypermobility-type than in Classical-type or Vascular-type.

Although all types are potentially life-threatening, the majority of individuals will have a normal lifespan. However, those with blood vessel fragility have a high risk of fatal complications. Arterial rupture is the most common cause of sudden death in EDS. Spontaneous arterial rupture most often occurs in the second or third decade, but can occur at any time. The median life-expectancy in the population with Vascular EDS is 48 years.

EDS is a lifelong condition. Affected individuals may face social obstacles related to their disease daily. Some people with EDS have reported living with fear of significant and painful ruptures, their condition worsening, becoming unemployed due to physical and emotional burdens, and social stigmatization in general.

Treatment

There is no cure for Ehlers Danlos Syndrome. Treatment is palliative. Close monitoring of the cardiovascular system, physiotherapy, occupational therapy, and orthopedic instruments (e.g., wheelchairs, bracing, casting) may be helpful. Orthopedic instruments are helpful for the prevention of further joint damage, especially for long distances, although it is advised that individuals not become dependent on them until there are no other options for mobility. One should avoid activities that cause the joint to lock or overextend.

A physician may prescribe casting to stabilize joints. Physicians may refer a patient to an orthotist for orthotic treatment (bracing). Physicians may also consult a physical and/or occupational therapist to help strengthen muscles and to teach people how to properly use and preserve their joints.

There are different types of physiotherapy. Aquatic therapy promotes muscular development and coordination. With manual therapy, the joint will be gently mobilized within the range of motion and/or manipulations. Electrotherapy like transcutaneous electrical nerve stimulation reduces local musculoskeletal pain.

If conservative therapy is not helpful, surgical repair of joints may be necessary. Medication to decrease pain or manage cardiac, digestive, or other related conditions may be prescribed. To decrease bruising and improve wound healing, some patients have responded to ascorbic acid (vitamin C). Special precautions are often taken by medical care workers because of the sheer amount of complications that tend to arise in EDS patients. In Vascular EDS, signs of chest or abdominal pain are to be considered trauma situations.

In general, medical intervention is limited to symptomatic therapy. Before pregnancy, patients with EDS should have genetic counseling. Children with EDS should be provided with information about the disorder so they can understand why contact sports and other physically stressful activities should be avoided. Children should be taught early on that demonstrating the unusual positions they can maintain due to loose joints should not be done as this may cause early degeneration of the joints. Patients may find it hard to cope with the drawbacks of the disease. In this case emotional support and behavioral and psychological therapy can be useful. Support groups can be immensely helpful for patients dealing with major lifestyle changes and poor health. Family members, teachers, and friends should be informed about EDS so they can accept and assist the child.

Despite all these types of conservative therapy, except bracing, results show that conservative therapy is ineffective in contrast to midcarpal instability in normal patients. L. Rombaut showed that in almost 40% of the cases, conservative therapy has a neutral or even a negative outcome. Conservative therapy may be unsuccessful in controlling instability in the longer term.

Surgery:
The instability of joints, leading to (sub)luxations and joint pain, often require surgical intervention in patients with Ehlers–Danlos syndrome. Instability of almost all joints can happen but appear most often in the lower and upper extremities, with the wrist, fingers, shoulder, knee, hip, and ankle being most common.

Common surgical procedures are joint debridement, tendon replacements, capsulorraphy and arthroplasty. Studies have shown that after surgery, degree of stabilization, pain reduction, and patient satisfaction can improve, but surgery does not guarantee an optimal result: Patients and surgeons report being dissatisfied with the results. Consensus is that conservative treatment is more effective than surgery, particularly since patients have extra risks of surgical complications due to the disease. Three basic surgical problems arise due to EDS: the strength of the tissues is decreased, which makes the tissue less suitable for surgery; the fragility of the blood vessels can cause problems during surgery; and wound healing is often delayed or incomplete.

Studies have shown that local anesthetics, arterial catheters and central venous catheters cause a higher risk in haematoma formation in patients with Ehlers–Danlos syndrome. Ehlers-Danlos patients also show a resistance to local anaesthetics. Special recommendations for anesthesia in EDS patients are prepared by orphan anesthesia.eu and deal with all aspects of anesthesia for EDS patients. Detailed recommendations for anesthesia and perioperative care of patients with EDS should be used to improve patient safety.

Surgery with Ehlers-Danlos patients requires careful tissue handling and a longer immobilization afterward.