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Schwartz-Jampel Syndrome

Background

Schwartz-Jampel syndrome (SJS) is a term now applied to 2 different inherited, autosomal recessive conditions, sometimes termed SJS type I and SJS type II. Both are very rare. SJS type I has 2 recognized subtypes, IA and IB, which are similar, except that type IB manifests earlier and with greater severity. (See Etiology.)

The first described cases of SJS were reported in 1962 by Oscar Schwartz and Robert S. Jampel in the Archives of Ophthalmology in an article titled “Congenital blepharophimosis associated with a unique generalized myopathy.”
In this paper, the authors presented the case of 2 siblings, a boy aged 6 years and a girl aged 3.5 years, who had the following clinical characteristics (see Presentation):

Congenital blepharophimosis – Ie, decreased palpebral fissure with normal eyelid development

Unusual facies characterized by a puckered facial appearance

Small muscle mass and joint deformities – Eg, coxa valga, irregularity of the capital femoral epiphyses, pectus carinatum (“pigeon breast”)

Hypertrichosis of the eyelids

Slightly elevated serum aldolase level

Electromyography (EMG) was not performed. The authors proposed that the disease might represent a generalized problem with muscle and tendon development during infancy.

SJS type I

The clinical features of muscle stiffness in SJS type I somewhat resemble those seen in myotonic disorders, stiff person syndrome, and Isaacs syndrome. The stiffness does not disappear with sleep or benzodiazepine treatment (as in stiff person syndrome), and it is not abolished reliably with curare (as in Isaacs syndrome). (See Presentation.)

Neurophysiologic examination typically shows continuous electrical activity (similar to myotonic discharges). However, the electrical activity often lacks the waxing and waning quality of true electrical myotonia and might be better described as complex, repetitive discharges. At other times, the pattern resembles neuromyotonia (ie, extremely rapid, repetitive discharges that wane from an initially high amplitude). In other cases, a combination of these and other electrical patterns are seen. Perhaps a unique Schwartz-Jampel pattern exists that has not yet been fully defined. (See Workup.)

In affected patients with type I, problems with motor development frequently become evident during the first year of life. Usually, the characteristic dysmorphic features lead to an early diagnosis, no later than age 3 years. SJS types IA and IB derive from mutations of the same gene, the HSPG2 gene, which codes for perlecan, a heparin sulfate proteoglycan.

Type IA

The most commonly recognized and described form of SJS is type IA, which exhibits muscle stiffness, mild (and largely nonprogressive) muscle weakness, and a number of minor morphologic abnormalities. Type IA is the classic type described by Schwartz and Jampel. It becomes apparent later in childhood and is less severe than type IB. (See Presentation.)

Type IB

Type IB is apparent immediately at birth and is clinically more severe, although it is typically compatible with life and even long-term survival.

SJS type II

SJS type II, like type IB, is apparent immediately at birth. The patients look similar to those with type IB. However, it has been known for many years that type II does not map to the same chromosome as types IA and IB. It is now known that type II relates to a mutation in a different gene, the gene for the leukemia inhibitory factor receptor (LIFR). This is the same disease as Stuve-Wiedemann syndrome, which has been known separately, mainly in the rheumatologic and orthopedic literature, rather than the neurologic literature. (See Etiology.)

The cardinal features of type II are joint contractures, bone dysplasia, and small stature. Infants with type II have severe respiratory difficulties and feeding problems. Hypotonia (rather than stiffness) is prominent. Frequent bouts of hyperthermia have been described (possibly related to mitochondrial dysfunction). (See Presentation.)

A high infant mortality rate is associated with this condition. Long-term survivors are rare but do exist, including 2 survivors, ages 3 and 12 years, reported on by Di Rocco et al in 2003.
In addition to problems with bone dysplasia, these 2 children manifested dysautonomic and neuropathic features, including reduced patellar reflexes, lack of corneal reflexes, and paradoxical perspiration at low temperatures. Their tongues lacked fungiform papillae (in addition to showing ulcerations). Reither et al reported on a survivor aged 16 years with SJS type II. (See Prognosis.)

Considerable justification can be made for dropping the term SJS type II and simply referring to the condition as Stuve-Wiedemann syndrome. The disease is not technically that which Schwartz and Jampel described. Nevertheless, the term SJS type II is included in this discussion. Because so few patients with Stuve-Wiedemann syndrome have survived long term, most of the clinical information provided in this article pertains to SJS types IA and IB. Information pertinent to Stuve-Wiedemann syndrome will be identified as such.

Patient education

Because patients with SJS have a characteristic physical appearance, they may need extra psychosocial support.

As in all diseases causing muscle stiffness, the danger exists of iatrogenic addiction to muscle relaxants such as diazepam (which is not particularly useful in this condition). If patients are treated with the medications listed in this article or with other medications, they should be educated about the drugs’ adverse effects. (See Treatment and Medication.)

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