Genetic identity of Marinesco-Sjögren/myoglobinuria and CCFDN syndromes

Severe Congenital Myopathy and Neuropathy with Congenital Cataracts due to GFER Variant: A Neuropathological Study

We describe the clinical, muscle and nerve biopsy, and genetic findings in a 10-year-old girl with a profound and rapid global regression. She presented during neonatal period with hypotonia, followed by weakness in the facial, bulbar, respiratory, and neck flexor muscles. She developed bilateral cataracts at 4 months of age and started to regress. Quadriceps muscle biopsy revealed extensive fiber atrophy but sparing of some, predominantly type 1, fibers. Sural nerve biopsy showed depletion of myelinated and unmyelinated fibers; most remaining myelinated fibers were of small caliber. Neuroimaging revealed global brain atrophy. Although the investigations indicated a multisystem disorder, extensive genetic and metabolic investigations were negative. She was tracheostomy- and ventilator-dependent for most of her life. The child died at 10 years of age. Further deoxyribonucleic acid analysis undertaken via whole genome sequencing revealed a novel pathogenic GFER sequence variant consistent with the patient's clinical presentation.

Anesthesia of a patient with congenital cataract, facial dysmorphism, and neuropathy syndrome for posterior scoliosis: A case report

BACKGROUND

Congenital cataract, facial dysmorphism, and neuropathy (CCFDN) syndrome is an extremely rare multiorgan disorder. Characteristics include congenital cataracts, facial deformation, extremity deformities, and demyelinating neuropathy. CCFDN syndrome is associated with increased risk during anesthesia including rhabdomyolysis or epileptic seizures. There is a lack of published information about difficult airways in these patients. Difficult airways during intubation represent one of the most dreaded anesthesia complications: A "can not intubate, can not oxygenate" scenario. Presented herein is the first described successful endotracheal intubation of a CCFDN syndrome patient.

CASE SUMMARY

We report the anesthetic management of a 13-year-old girl with CCFDN syndrome scheduled for posterior neuromuscular scoliosis correction surgery. The patient suffered from extensive progressive neuromuscular scoliosis with a Cobb angle of 83°. Her limitations included neuropathy and a scoliotic curve. This condition negatively impacted her quality of life. This case reflects the potential anesthetic complications for posterior scoliosis correction and CCFDN syndrome. The challenge for our anesthetic team was the limited amount of data about anesthetic management of this condition. In total, one case report without any data about endotracheal intubation of patients with this condition was available. Endotracheal intubation in our case was uncomplicated. Another focus of our case was the prevention of possible complications associated with this syndrome, including rhabdomyolysis and seizures. Rhabdomyolysis can be triggered by some types of anesthetic agents like suxamethonium or volatile anesthetics, especially in patients with certain types of myopathies.

CONCLUSION

Adequate understanding of the anesthetic management of CCFDN syndrome can reduce perioperative complications and improve patient outcome after surgery.

Ataxia

Ataxia is a disorder of balance and coordination resulted from dysfunctions involving cerebellum and its afferent and efferent connections. While a variety of disorders can cause secondary ataxias, the list of genetic causes of ataxias is growing longer. Genetic abnormalities may involve mitochondrial dysfunction, oxidative stress, abnormal mechanisms of DNA repair, possible protein misfolding, and abnormalities in cytoskeletal proteins. Few ataxias are fully treatable while hope for efficacious gene therapy and pharmacotherapy is emerging. A discussion of the ataxias is presented here with brief mention of acquired ataxias, and a greater focus on inherited ataxias.

Rhabdomyolysis: a genetic perspective

Rhabdomyolysis (RM) is a clinical emergency characterized by fulminant skeletal muscle damage and release of intracellular muscle components into the blood stream leading to myoglobinuria and, in severe cases, acute renal failure. Apart from trauma, a wide range of causes have been reported including drug abuse and infections. Underlying genetic disorders are also a cause of RM and can often pose a diagnostic challenge, considering their marked heterogeneity and comparative rarity.

In this paper we review the range of rare genetic defects known to be associated with RM. Each gene has been reviewed for the following: clinical phenotype, typical triggers for RM and recommended diagnostic approach. The purpose of this review is to highlight the most important features associated with specific genetic defects in order to aid the diagnosis of patients presenting with hereditary causes of recurrent RM.

Other autosomal recessive and childhood ataxias

The label of "early-onset cerebellar ataxia with retained tendon reflexes" (EOCA) has been created to differentiate it from Friedreich ataxia (FRDA) patients with preserved knee jerks and absence of cardiomyopathy, optic atrophy, and diabetes mellitus. However, EOCA is a heterogeneous syndrome and several FRDA patients present with an EOCA-like phenotype. Cerebellar ataxia with hypogonadism is another heterogeneous syndrome for which no locus has been mapped yet. Two peculiar ataxic syndromes have been identified in genetically isolated populations: autosomal recessive ataxia of Charlevoix-Saguenay (ARSACS) in Quebec and infantile-onset spinocerebellar ataxia (IOSCA) in Finland. Both conditions present usually within the second year of life. ARSACS is characterized by marked spasticity and IOSCA by a complex phenotype which includes, besides ataxia, epilepsy, optic atrophy, ophthalmoplegia, hearing loss, and areflexia. The responsible genes are SACS, encoding sacsin, a protein which may act as a chaperone, and C10orf2, encoding Twinkle, a mitochondrial DNA-specific helicase. Marinesco-Sjögren syndrome, clinically characterized by cerebellar ataxia, cataracts, myopathy, and mental retardation, is genetically heterogeneous. One gene, SIL1, encodes a nucleotide exchange factor for the heat-shock protein 70 chaperone HSPA5. Five conditions account for most cases of progressive myoclonic ataxia: Unverricht-Lundborg disease, Lafora disease, myoclonic epilepsy with ragged-red fibers, neuronal ceroid lipofuscinoses, and sialidoses.

Progressive cerebral white matter involvement in a patient with Congenital Cataracts Facial Dysmorphisms Neuropathy (CCFDN)

Congenital Cataracts with Facial Dysmorphisms and Neuropathy (CCFDN) is a complex autosomal recessive disorder characterized by bilateral congenital cataracts, developmental delay, peripheral; hypo-demyelinating neuropathy, mild facial dysmorphisms, and other rare signs. Cerebral and spinal cord atrophy is the main neuroimaging finding but other less common abnormalities have been previously described. We describe progressive focal lesions of supratentorial white matter in a 10-year-old boy affected by CCFDN. Other etiologies have been excluded and these lesions can be considered a new finding of the disease. We discuss a possible demyelinating mechanism affecting both peripheral and central myelin.

Marinesco-Sjögren syndrome with atrophy of the brain stem tegmentum and dysplastic cytoarchitecture in the cerebral cortex

Marinesco-Sjögren syndrome (MSS) is a progressive multisystem disease with autosomal recessive inheritance characterized by cataracts, mental retardation, and cerebellar ataxia. Recently, two causative genes for MSS, SIL1 and SARA2, have been identified. On the other hand, the histopathologic features of the CNS in this syndrome have not yet been clarified in detail. We report here the features of an autopsy case of MSS with progressive myopathy, in which atrophy of the cerebellum and brain stem tegmentum, retinal degeneration, and dysplastic cytoarchitecture in the cerebral cortex were evident. An elder brother of the patient showed quite similar symptoms, implying an autosomal recessive mode of inheritance. However, we detected no mutations in the available genes. This case appears to represent an unusual example of MSS manifesting widespread developmental anomaly and neuronal degeneration in the CNS.

Congenital cataracts facial dysmorphism neuropathy (CCFDN) syndrome: a rare cause of parainfectious rhabdomyolysis

Congenital cataracts-facial dysmorphism-neuropathy syndrome (CCFDN, MIM: 604168), is a recently delineated neurogenetic disease causing recurrent episodes of rhabdomyolysis; prevention and early diagnosis of rhabdomyolysis should be part of the clinical management of the disease.

Autosomal recessive cerebellar ataxias

Autosomal recessive cerebellar ataxias (ARCA) are a heterogeneous group of rare neurological disorders involving both central and peripheral nervous system, and in some case other systems and organs, and characterized by degeneration or abnormal development of cerebellum and spinal cord, autosomal recessive inheritance and, in most cases, early onset occurring before the age of 20 years. This group encompasses a large number of rare diseases, the most frequent in Caucasian population being Friedreich ataxia (estimated prevalence 2–4/100,000), ataxia-telangiectasia (1–2.5/100,000) and early onset cerebellar ataxia with retained tendon reflexes (1/100,000). Other forms ARCA are much less common. Based on clinicogenetic criteria, five main types ARCA can be distinguished: congenital ataxias (developmental disorder), ataxias associated with metabolic disorders, ataxias with a DNA repair defect, degenerative ataxias, and ataxia associated with other features. These diseases are due to mutations in specific genes, some of which have been identified, such as frataxin in Friedreich ataxia, α-tocopherol transfer protein in ataxia with vitamin E deficiency (AVED), aprataxin in ataxia with oculomotor apraxia (AOA1), and senataxin in ataxia with oculomotor apraxia (AOA2). Clinical diagnosis is confirmed by ancillary tests such as neuroimaging (magnetic resonance imaging, scanning), electrophysiological examination, and mutation analysis when the causative gene is identified. Correct clinical and genetic diagnosis is important for appropriate genetic counseling and prognosis and, in some instances, pharmacological treatment. Due to autosomal recessive inheritance, previous familial history of affected individuals is unlikely. For most ARCA there is no specific drug treatment except for coenzyme Q10 deficiency and abetalipoproteinemia.

Congenital cataracts-facial dysmorphism-neuropathy

Congenital Cataracts Facial Dysmorphism Neuropathy (CCFDN) syndrome is a complex developmental disorder of autosomal recessive inheritance. To date, CCFDN has been found to occur exclusively in patients of Roma (Gypsy) ethnicity; over 100 patients have been diagnosed. Developmental abnormalities include congenital cataracts and microcorneae, primary hypomyelination of the peripheral nervous system, impaired physical growth, delayed early motor and intellectual development, mild facial dysmorphism and hypogonadism. Para-infectious rhabdomyolysis is a serious complication reported in an increasing number of patients. During general anaesthesia, patients with CCFDN require careful monitoring as they have an elevated risk of complications. CCFDN is a genetically homogeneous condition in which all patients are homozygous for the same ancestral mutation in the CTDP1 gene. Diagnosis is clinical and is supported by electrophysiological and brain imaging studies. The major differential diagnosis is Marinesco-Sjögren syndrome. The definitive diagnosis is molecular, based on homozygosity for the CTDP1 mutation. CTDP1 maps to 18qter and encodes a protein phosphatase whose only known substrate is the phosphorylated serine residues of the carboxy-terminal domain of the largest subunit of RNA polymerase II, indicating that CCFDN affects basic cellular processes of gene expression and developmental regulation. Families benefit from genetic counselling and predictive testing. Management includes surgical treatment of the cataracts, and rehabilitation and corrective orthopaedic surgery for the peripheral neuropathy. Thus, the most disabling manifestations, though not curable, are manageable, and allow an acceptable quality of life and everyday living. Current data indicate that patients survive well into adulthood.

Cataracts, ataxia, short stature, and mental retardation in a Chinese family mapped to Xpter-q13.1

Six males in a Chinese family affected by congenital cataracts, cerebellar ataxia, short stature, and mental retardation, which were tentatively named CASM syndrome. Eight female carriers in the family had cataracts alone. Linkage analysis demonstrated that the disease is transmitted through X-linked inheritance, either by setting the syndrome in males as an X-linked recessive trait, or by setting cataracts in the family as an X-linked dominant trait. The gene responsible for the syndrome is mapped to Xpter-Xq13.1, with the highest lod score of 3.91 for DXS1226, DXS991, and DXS1213 at theta = 0. Haplotype analysis identified that the allele harboring the disease gene co-segregated with all female carriers as well as affected males in the family. Clinically and genetically, the disease in this family is different from any known disease. Major features of CASM syndrome that distinguish it from other diseases are X-linked inheritance and cataracts in carrier females.

Congenital cataract facial dysmorphism neuropathy syndrome: a clinically recognizable entity

Congenital cataracts facial dysmorphism neuropathy syndrome is a recently delineated autosomal recessive condition exclusively found in the Gypsy population. Congenital cataracts facial dysmorphism neuropathy syndrome is caused by a homozygous mutation in the CTDP1 gene, leading to disruption of the ribonucleic acid transcription machinery. This report presents a young Gypsy female affected by this rare disorder. Electromyography and sural nerve histology were in accordance with a hypomyelinating neuropathy. After clinical recognition of congenital cataracts facial dysmorphism neuropathy syndrome some years ago, we recently demonstrated the presence of the homozygous IVS6+389C-->T mutation in the CTDP1 gene in this family.

Myopathy is a prominent feature in Marinesco-Sjögren syndrome: A muscle computed tomography study

BACKGROUND

Marinesco-Sjögren syndrome (MSS) is an autosomal recessive multiorgan disorder showing clinical and genetic heterogeneity. The key features of MSS include cerebellar ataxia, early bilateral cataracts, delayed motor development, and varying degrees of mental retardation. Patients with a subtype of MSS with myoglobinuria and neuropathy have been linked to chromosome 18qter, and recently a locus for classical MSS has been localized on chromosome 5q31.

OBJECTIVES

To determine the importance of myopathy in this disorder apart from the CNS based disability and to establish the pattern of muscle involvement and degree of its severity.

METHODS

Muscle computed tomography (CT) investigations were carried out in nine Finnish MSS patients homozygous for markers around the MSS locus on chromosome 5q31.

RESULTS

Patients with severe clinical disability showed severe and generalized muscle degeneration. Muscle CT findings in patients with relatively severe clinical picture were characterized by severe involvement of the posterior thoracic and pelvic muscles, and almost all thigh muscles. In the legs the peronei and posterior compartment muscles were severely degenerated. The group of patients with moderate severity of disease showed the same pattern of involved muscle, albeit with lower degree of muscle degeneration.

CONCLUSIONS

Patients with MSS linked to chromosome 5q31 have a severe progressive myopathy, the extent of which may remain largely unrecognized because of the CNS involvement.

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.

Vlax Roma history: what do coalescent-based methods tell us?

Three coalescent-based methods allowed us to infer some aspects of the history of three Bulgarian Gypsies populations belonging to the Vlax linguistic group: the Lom, Rudari and Kalderas. We used several kinds of genetic markers: HV1 sequences of the maternally inherited mitochondrial genome and microsatellites of the paternally inherited Y chromosome and of the biparentally inherited chromosome 8. This allowed us to infer several parameters for men and women: the splitting order of the populations and the ages of the splitting events, the growth rate in each population and the migration rates between populations. Altogether, they enabled us to infer a demographic scenario that could explain the genetic diversity of Vlax Roma: recent splits occurring after the arrival in Europe, asymmetric migration flows especially for males and unequal growth rates. This represents a considerable contribution to the Vlax Roma history in comparison with the inferences from classical population genetics.

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 landmarks through philately: Georges Marinesco (1863-1938)

Georges Marinesco was one of Romania's most eminent physicians and an accomplished neurologist. He had diverse interests in anatomy and neuropathology. He has been honored on postage stamps issued by his birth nation on several occasions. Neurologists and geneticists know of him for the rare familial degenerative neurological disorder that has been named after him, the Marinesco-Sjögren syndrome.

Partial deficiency of the C-terminal-domain phosphatase of RNA polymerase II is associated with congenital cataracts facial dysmorphism neuropathy syndrome

Congenital cataracts facial dysmorphism neuropathy (CCFDN) syndrome (OMIM 604168) is an autosomal recessive developmental disorder that occurs in an endogamous group of Vlax Roma (Gypsies; refs. 1-3). We previously localized the gene associated with CCFDN to 18qter, where a conserved haplotype suggested a single founder mutation. In this study, we used recombination mapping to refine the gene position to a 155-kb critical interval. During haplotype analysis, we found that the non-transmitted chromosomes of some unaffected parents carried the conserved haplotype associated with the disease. Assuming such parents to be completely homozygous across the critical interval except with respect to the disease-causing mutation, we developed a new 'not quite identical by descent' (NQIBD) approach, which allowed us to identify the mutation causing the disease by sequencing DNA from a single unaffected homozygous parent. We show that CCFDN is caused by a single-nucleotide substitution in an antisense Alu element in intron 6 of CTDP1 (encoding the protein phosphatase FCP1, an essential component of the eukaryotic transcription machinery), resulting in a rare mechanism of aberrant splicing and an Alu insertion in the processed mRNA. CCFDN thus joins the group of 'transcription syndromes' and is the first 'purely' transcriptional defect identified that affects polymerase II-mediated gene expression.