Sensorimotor neuropathy in a patient with Marinesco-Sjögren syndrome

Neuropathology of Charcot-Marie-Tooth and related disorders

The peripheral nervous system (PNS), with all its branches and connections, is so complex that it is impossible to study all components at the light or electron microscopic level in any individual case; nevertheless, in certain diseases a simple nerve biopsy may suffice to arrive at a precise diagnosis. Structural changes of the PNS in neuropathies of the Charcot-Marie-Tooth (CMT) type and related disorders comprise various components of the PNS. These include peripheral motor, sensory, and autonomous neurons with their axons, Schwann cells, and myelin sheaths in the radicular and peripheral nerves as well as satellite cells in spinal and autonomous ganglia. Astrocytes, oligodendroglial cells, and microglial cells around motor neurons in the anterior horn and around sensory neurons in other areas of the spinal cord are also involved. In addition, connective tissue elements such as endoneurial, perineurial, and epineurial components including blood and lymph vessels play an important role. This review focuses on the cellular components and organelles involved, that is, myelin sheaths, axons with their micro-tubules and neurofilaments; nuclei, mitochondria, endoplasmic reticulum, and connective tissue including the perineurium and blood vessels. A major role is attributed to recent progress in the pathomorphology of various types of CMT1, 2,4, CMTX, and HMNSL, based on light and electron microscopic findings, morphometry, teased fiber studies, and new immunohisto-chemical results such as staining of certain periaxin domains in CMT4F.

Marinesco-Sjögren syndrome in a male with mild dysmorphism

Marinesco-Sjogren syndrome (MSS) is a rare, autosomal recessive disorder comprising cataracts, cerebellar ataxia caused by cerebellar hypoplasia, mild to moderate mental retardation, neuromuscular weakness, short stature, hypergonadotrophic hypogonadism, and skeletal anomalies. The syndrome was recently mapped to chromosome 5q31, but there is evidence for genetic heterogeneity, and no gene has been identified. We report a 5-year-old male with cataracts, ataxia, a progressive cerebellar atrophy, developmental delay, seizures, hypotonia, and a sensorimotor neuropathy consistent with many cases of MSS. He also had mild craniofacial dysmorphism consisting of hypertrichosis and synophrys, deep-set eyes with epicanthic folds, a flat philtrum, a high palate, short thumbs, and a wide sandal gap between the first and second toes. Skeletal findings included an increased kyphosis. We reviewed the literature on MSS to determine if craniofacial dysmorphism and the presence of neuropathy and/or myopathy would prove to be diagnostically useful in this phenotypically heterogeneous condition. The majority of cases of MSS do not have craniofacial dysmorphism, but other cases have been reported with features such as ptosis or a myopathic facies that are likely to reflect the underlying myopathic or neuromuscular processes in MSS.

Ocular features of the congenital cataracts facial dysmorphism neuropathy syndrome

OBJECTIVE

To determine the nature and course of ophthalmologic abnormalities in congenital cataracts facial dysmorphism neuropathy (CCFDN) syndrome in a genetically verified group of 9 patients.

STUDY DESIGN

Observational case series.

PARTICIPANTS

Nine affected male individuals of 5 pedigrees aged 1.3 to 16.8 years were examined. Four individuals were recruited during an ongoing prospective study of congenital cataracts; 5 individuals could be assigned to the CCFDN group on the basis of our retrospective data.

MAIN OUTCOME MEASURES

Linkage and haplotype analysis, neurologic examinations, bilateral cataracts, axial length, corneal diameter, pupil diameter and pupillary reactions, intraoperative and postoperative complications, lid changes, aphakic correction problems, refractive results, and visual function.

RESULTS

All families originated from the eastern part of Serbia, close to the border with Romania. The 8 tested individuals were homozygous for the conserved ancestral CCFDN haplotype in the telomeric region of chromosome 18q. All patients showed a peripheral, demyelinating neuropathy and varying degrees of ataxia. In the older patients, muscular atrophy in distal muscles and facial dysmorphism was evident. Early-onset bilateral congenital cataracts associated with microcornea, microphthalmos, and micropupil could be found in all patients. All children had floppy eyelid syndrome and pseudoptosis. An increased inflammatory reaction to contact lenses and intraocular lenses could be documented in all. All patients had syndrome-associated nystagmus and congenital esotropia. Distant visual acuity could be classified as severe to moderate impairment, whereas near visual acuity was much better (mild to moderate impairment).

CONCLUSIONS

Early-onset congenital cataracts associated with microcornea, microphthalmos, and micropupil are essential ocular features of the CCFDN syndrome and are the first recognizable signs during early infancy. Awareness of this syndrome by pediatric ophthalmologists is important, because these typical findings, combined with information on ethnic origin, may lead to very early diagnosis at an age when the nature and severity of nonophthalmologic features are not apparent. Affected individuals may benefit from careful ophthalmologic treatment and follow-up, as well as from early management of the neurologic problems and developmental delay. Affected families will benefit from genetic counseling and predictive testing.

Homozygosity mapping of Marinesco-Sjögren syndrome to 5q31

Marinesco-Sjögren syndrome (MSS), first described in 1931, is an autosomal recessive condition characterised by somatic and mental retardation, congenital cataracts and cerebellar ataxia. Progressive myopathy was later reported to be also a cardinal sign of MSS, with myopathic changes on muscle biopsies. Hypergonadotrophic hypogonadism and skeletal deformities related to pronounced hypotonia were also reported. The major differential diagnosis of MSS is the syndrome defined by congenital cataracts, facial dysmorphism and peripheral neuropathy (CCFDN), which is localised to 18qter. Using homozygosity mapping strategy in two large consanguineous families of Turkish and Norwegian origin, respectively, we have identified the MSS locus on chromosome 5q31. LOD score calculation, including the consanguinity loops, gave a maximum value of 2.9 and 5.6 at theta=0 for the Turkish and the Norwegian families, respectively, indicating linkage between the disease and the D5S1995-D5S436 haplotype spanning a 9.3 cM interval. Patients of the two families presented with the strict clinical features of MSS. On the other hand, the study of two smaller French and Italian families, initially diagnosed as presenting an atypical MS syndrome, clearly excluded linkage from both the MSS locus on 5q31 and the CCFDN locus in 18qter. Patients of the two excluded families had all MSS features (but the myopathic changes) plus peripheral neuropathy and optic atrophy, and various combinations of microcornea, hearing impairment, seizures, Type I diabetes, cerebral atrophy and leucoencephalopathy, indicating that only the pure MSS syndrome is a homogeneous genetic entity.

Genetic identity of Marinesco-Sjögren/myoglobinuria and CCFDN syndromes

OBJECTIVE AND BACKGROUND

To describe three Gypsy families with Marinesco-Sjögren syndrome (MSS), demyelinating neuropathy, and recurrent episodes of myoglobinuria in five of the six affected subjects. Because these families originated from the same genetically isolated founder population as did patients with congenital cataracts facial dysmorphism neuropathy (CCFDN) syndrome, and because the two syndromes have clinical manifestations in common, we hypothesized that the two related, albeit distinct, syndromes may represent clinical variants of a single genetic disorder.

METHODS

Clinical studies were conducted and linkage and haplotype analyses were performed for the three families. A total of 16 individuals, including the 6 with MSS and 10 unaffected relatives, were genotyped for six polymorphic microsatellite markers from the CCFDN region on 18qter.

RESULTS

Linkage analysis of markers in the 18qter region, where we previously had located the CCFDN gene, produced a lod score of 3.55, demonstrating colocalization of the gene responsible for MSS with demyelinating neuropathy and myoglobinuria with the CCFDN gene. Moreover, the patients with MSS shared the conserved marker haplotype found in CCFDN chromosomes.

CONCLUSIONS

These data suggest that Marinesco-Sjögren syndrome with peripheral neuropathy and myoglobinuria, and congenital cataracts facial dysmorphism neuropathy syndrome are genetically identical and are caused by a single founder mutation.

Marinesco-Sjögren syndrome in a Bedouin family

Marinesco-Sjögren syndrome is rarely reported in the Middle East. This is the 2nd report of Marinesco-Sjögren syndrome in an Arab family. The clinical features of 2 affected brothers are described. Electrophysiological studies of the 2 patients showed primarily myopathic changes, whereas sural nerve biopsy revealed segmental demyelination and axonal degeneration. The role of tissue biopsy and the relationship to different electrophysiological studies are discussed. Both patients were noticed to have abnormally short lateral 3 metatarsals, a feature not present in other healthy members of the family. We suggest that this feature should be considered part of the syndrome profile.

Marinesco-Sjögren syndrome: clinical and magnetic resonance imaging features in three children

The authors describe clinical and MRI features of a girl and two boys, aged 9, 17 and 19 years, respectively, with Marinesco-Sjögren syndrome. The clinical findings included the major features of the syndrome, including growth deficiency, ataxia, cataracts, hypogonadism (in two) and seizures (in two). Truncal hypotonia (in three), microcephaly (in two) and leg spasticity (in two) were also present. MRI showed a very small cerebellar vermis in all three patients, various supratentorial abnormalities, an apparently small anterior pituitary gland in two and the absence of a posterior pituitary gland in all three. The MRI features are similar to the few reported pathologic findings for persons with Marinesco-Sjögren syndrome. MRI may be helpful in the early diagnosis of the disorder.

Marinesco-Sjögren syndrome: clinical and magnetic resonance imaging features in three children

The authors describe clinical and MRI features of a girl and two boys, aged 9, 17 and 19 years, respectively, with Marinesco-Sjögren syndrome. The clinical findings included the major features of the syndrome, including growth deficiency, ataxia, cataracts, hypogonadism (in two) and seizures (in two). Truncal hypotonia (in three), microcephaly (in two) and leg spasticity (in two) were also present. MRI showed a very small cerebellar vermis in all three patients, various supratentorial abnormalities, an apparently small anterior pituitary gland in two and the absence of a posterior pituitary gland in all three. The MRI features are similar to the few reported pathologic findings for persons with Marinesco-Sjögren syndrome. MRI may be helpful in the early diagnosis of the disorder.

Myopathy in Marinesco-Sjögren syndrome: an electrophysiological study

Electrophysiological studies were performed in 7 patients with Marinesco-Sjögren syndrome in order to search for neuromuscular involvement in this multiorgan disorder. In 6 patients muscle biopsies were also obtained. Light microscopic examinations of the biopsies showed extensive myopathic changes, and in two patients ragged red fibers were found. Electron microscopy showed subsarcolemmal accumulation of abnormal mitochondria in all. Concentric needle EMG revealed unequivocal myopathic changes, more extensive in the anterior tibial than in the biceps brachii muscle. Motor and sensory conduction velocities in the peripheral nerves were normal. There were remarkably high amplitudes of sensory responses. Macro EMG studies in the biceps brachii muscle in four patients showed increased amplitude and area of the macro MUPs. This may be due to abnormal membrane function. Both electrophysiological and morphological findings confirm myopathic features of Marinesco-Sjögren syndrome.

AAEM minimonograph #34: polyneuropathy: classification by nerve conduction studies and electromyography

Electrodiagnostic evaluation of patients with suspected polyneuropathy is useful for detecting and documenting peripheral abnormalities, identifying the predominant pathophysiology, and determining the prognosis for certain disorders. The electrodiagnostic classification of polyneuropathy is associated with morphologic correlates and is based upon determining involvement of sensory and motor fibers and distinguishing between predominantly axon loss and demyelinating lesions. Accurate electrodiagnostic classification leads to a more focused and expedient identification of the etiology of polyneuropathy in clinical situations.

Polyneuropathies in paediatrics

Non-acute polyneuropathies (PNPs) encountered in paediatrics are reviewed. Emphasis is placed on three main groups of conditions: the relatively rare but treatable dysimmune PNP (chronic relapsing dysimmune polyneuropathies, CRDP); the more common hereditary motor/sensory neuropathies (HMSN and HSN); and the often missed symptomatic neuropathies of some heredodegenerative and neurometabolic disorders. Diagnostic procedures are discussed. One conclusion drawn is that so far metabolic screening procedures do not give any diagnostic or aetiological information in HMSN or in HSN, nor in heredoataxias or heredoparaplegias. When a specific neurometabolic disease is suspected from the clinical symptomatology, individually structured investigations are necessary.

Myopathy with unique ultrastructural feature in Marinesco-Sjögren syndrome

We have investigated 3 children aged 6, 3, and 2 years, from 2 families, with the clinical features of Marinesco-Sjögren syndrome. Muscle biopsy specimens from all 3 were abnormal and showed small vacuoles and slight variation in fiber size. Electron microscopy revealed vacuolation and membranous whorls and, in particular, a unique dense membranous structure associated with nuclei. These cases emphasize the involvement of muscle in Marinesco-Sjögren syndrome and the importance of electron microscopy in differential diagnosis.