Freeman–Sheldon syndrome

Freeman–Sheldon syndrome
Classification and external resources
Specialty
ICD-9-CM	759.89
OMIM	193700
DiseasesDB	31817
Patient UK	Freeman–Sheldon syndrome

Freeman–Sheldon syndrome (FSS), also termed distal arthrogryposis type 2A (DA2A), craniocarpotarsal dysplasia (or dystrophy), Cranio-carpo-tarsal syndrome, Windmill-Vane-Hand syndrome, or Whistling-face syndrome, was originally described by Freeman and Sheldon in 1938. Freeman–Sheldon syndrome is a rare form of multiple congenital contracture (MCC) syndromes (arthrogryposes) and is the most severe form of distal arthrogryposis (DA).

Signs and symptoms

The symptoms of Freeman–Sheldon syndrome include drooping of the upper eyelids, strabismus, low-set ears, a long philtrum, gradual hearing loss, scoliosis, and walking difficulties. Gastroesophageal reflux has been noted during infancy, but usually improves with age. The tongue may be small, and the limited movement of the soft palate may cause nasal speech. Often there is an H- or Y-shaped dimpling of the skin over the chin.

Diagnosis

Freeman–Sheldon syndrome is a type of distal arthrogryposis, related to distal arthrogryposis type 1 (DA1). In 1996, more strict criteria for the diagnosis of Freeman–Sheldon syndrome were drawn up, assigning Freeman–Sheldon syndrome as distal arthrogryposis type 2A (DA2A).

On the whole, DA1 is the least severe; DA2B is more severe with additional features that respond less favourably to therapy. DA2A (Freeman–Sheldon syndrome) is the most severe of the three, with more abnormalities and greater resistance to therapy.

Freeman–Sheldon syndrome has been described as a type of congenital myopathy.

In March 2006, Stevenson et al. published strict diagnostic criteria for distal arthrogryposis type 2A (DA2A) or Freeman–Sheldon syndrome. These included two or more features of distal arthrogryposis: microstomia, whistling-face, nasolabial creases, and 'H-shaped' chin dimple.

Cause

FSS is caused by genetic changes. Krakowiak et al. (1998) mapped the distal arthrogryposis multiplex congenita (DA2B; MIM #601680) gene, a syndrome very similar in phenotypic expression to classic FSS, to 11p15.5-pter. Other mutations have been found as well. In FSS, inheritance may be either autosomal dominant, most often demonstrated. or autosomal recessive (MIM 277720). Alves and Azevedo (1977) note most reported cases of DA2A have been identified as new allelic variation. Toydemir et al. (2006) showed that mutations in embryonic myosin heavy chain 3 (MYH3; MIM *160270), at 17p-13.1-pter, caused classic FSS phenotype, in their screening of 28 (21 sporadic and 7 familial) probands with distal arthrogryposis type 2A. In 20 patients (12 and 8 probands, respectively), missense mutations (R672H; MIM *160270.0001 and R672C; MIM *160270.0002) caused substitution of arg672, an embryonic myosin residue retained post-embryonically. Of the remaining 6 patients in whom they found mutations, 3 had missense private de novo (E498G; MIM *160270.0006 and Y583S) or familial mutations (V825D; MIM *160270.0004); 3 other patients with sporadic expression had de novo mutations (T178I; MIM *160270.0003), which was also found in DA2B; 2 patients had no recognized mutations.

Management

Surgical and anaesthetic considerations

Patients must have early consultation with craniofacial and orthopaedic surgeons, when craniofacial, clubfoot, or hand correction is indicated to improve function or aesthetics. Operative measures should be pursued cautiously, with avoidance of radical measures and careful consideration of the abnormal muscle physiology in Freeman–Sheldon syndrome. Unfortunately, many surgical procedures have suboptimal outcomes, secondary to the myopathy of the syndrome.

When operative measures are to be undertaken, they should be planned for as early in life as is feasible, in consideration of the tendency for fragile health. Early interventions hold the possibility to minimise developmental delays and negate the necessity of relearning basic functions.

Due to the abnormal muscle physiology in Freeman–Sheldon syndrome, therapeutic measures may have unfavourable outcomes. Difficult endotracheal intubations and vein access complicate operative decisions in many DA2A patients, and malignant hyperthermia (MH) may affect individuals with FSS, as well. Cruickshanks et al. (1999) reports uneventful use of non-MH-triggering agents. Reports have been published about spina bifida occulta in anaesthesia management and cervical kyphoscoliosis in intubations.

Psychiatric considerations

Patients and their parents must receive psychotherapy, which should include marriage counselling. Mitigation of lasting psychological problems, including depression secondary to chronic illness and posttraumatic stress disorder (PTSD), can be very successfully addressed with early interventions. This care may come from the family physician, or other attending physician, whoever is more appropriate; specialist care is generally not required. Lewis and Vitulano (2003) note several studies suggesting predisposal for psychopathology in paediatric patients with chronic illness. Esch (2002) advocates preventive psychiatry supports to facilitate balance of positive and negative stressors associated with chronic physical pathology. Patients with FSS should have pre-emptive and ongoing mixed cognitive therapy-psychodynamic psychotherapy for patients with FSS and cognitive-behavioural therapy (CBT), if begun after onset of obvious pathology.

Adler (1995) cautioned the failure of modern medicine to implement the biopsychosocial model, which incorporates all aspects of a patient’s experience in a scientific approach into the clinical picture, often results in chronically-ill patients deferring to non-traditional and alternative forms of therapy, seeking to be understood as a whole, not a part, which may be problematic among patients with FSS.

Furthermore, neuropsychiatry, physiological, and imaging studies have shown PTSD and depression to be physical syndromes, in many respects, as they are psychiatric ones in demonstrating limbic system physiological and anatomy disturbances. Attendant PTSD hyperarousal symptoms, which additionally increase physiological stress, may play a part in leading to frequent MH-like hyperpyrexia and speculate on its influence on underlying myopathology of FSS in other ways. PTSD may also bring about developmental delays or developmental stagnation, especially in paediatric patients.

With psychodynamic psychotherapy, psychopharmacotherapy may need to be considered. Electroconvulsive therapy (ECT) is advised against, in light of abnormal myophysiology, with predisposal to MH.

Medical emphasis

General health maintenance should be the therapeutic emphasis in Freeman–Sheldon syndrome. The focus is on limiting exposure to infectious diseases because the musculoskeletal abnormalities make recovery from routine infections much more difficult in FSS. Pneumonitis and bronchitis often follow seemingly mild upper respiratory tract infections. Though respiratory challenges and complications faced by a patient with FSS can be numerous, the syndrome’s primary involvement is limited to the musculoskeletal systems, and satisfactory quality and length of life can be expected with proper care.

Prognosis

There are little data on prognosis. Rarely, some patients have died in infancy from respiratory failure; otherwise, life expectancy is considered to be normal.

Epidemiology

By 1990, 65 patients had been reported in the literature, with no sex or ethnic preference notable. Some individuals present with minimal malformation; rarely patients have died during infancy as a result of severe central nervous system involvement or respiratory complications. Several syndromes are related to the Freeman–Sheldon syndrome spectrum, but more information is required before undertaking such nosological delineation.

Research directions

One research priority is to determine the role and nature of malignant hyperthermia in FSS. Such knowledge would benefit possible surgical candidates and the anaesthesiology and surgical teams who would care for them. MH may also be triggered by stress in patients with muscular dystrophies. Much more research is warranted to evaluate this apparent relationship of idiopathic hyperpyrexia, MH, and stress. Further research is wanted to determine epidemiology of psychopathology in FSS and refine therapy protocols.

Eponym

It is named for Ernest Arthur Freeman (1900-1975), British Orthopedic Surgeon and Joseph Harold Sheldon (1920-1964), British Physician.

External links

• [1] from the Freeman-Sheldon Research Group, Inc. (FSRG) The Freeman-Sheldon Parent Support Group dissolved in Jan. 2011, after 29 years of operation. Records and services were transferred to the FSRG.