Brown-Vialetto-Van Laere syndrome in a large inbred Lebanese family: confirmation of autosomal recessive inheritance?

[Amyotrophic lateral sclerosis-Motor neuron disease with a wide clinical and genetic spectrum]

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is the most frequent motor neuron disease. Besides a timely diagnosis, precise knowledge of the clinical manifestations and differential diagnoses is essential. While most patients develop the disease at an older age, hereditary causes play a more frequent role in the juvenile forms.

OBJECTIVE

What is the current state of ALS diagnostics, which new treatment options exist?

MATERIAL AND METHOD

Literature search using Pubmed.gov.

RESULTS

The main focus is on an individualized symptomatic treatment as no curative treatment approaches exist. However, new insights into the genetic and pathophysiological principles of the different forms of ALS open the way for future disease-modifying treatment options.

CONCLUSION

In cases of a clinical suspicion of ALS molecular genetic diagnostics should be considered, particularly in juvenile and young adult patients, to exclude differential diagnoses and to enable patients access to new treatment approaches.

Recent advances in riboflavin transporter RFVT and its genetic disease

Riboflavin (vitamin B2) is essential for cellular growth and function. It is enzymatically converted to flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which participate in the metabolic oxidation-reduction reactions of carbohydrates, amino acids, and lipids. Human riboflavin transporters RFVT1, RFVT2, and RFVT3 have been identified and characterized since 2008. They are highly specific transporters of riboflavin. RFVT3 has functional characteristics different from those of RFVT1 and RFVT2. RFVT3 contributes to absorption in the small intestine, reabsorption in the kidney, and transport to the fetus in the placenta, while RFVT2 mediates the tissue distribution of riboflavin from the blood. Several mutations in the SLC52A2 gene encoding RFVT2 and the SLC52A3 gene encoding RFVT3 were found in patients with a rare neurological disorder known as Brown-Vialetto-Van Laere syndrome. These patients commonly present with bulbar palsy, hearing loss, muscle weakness, and respiratory symptoms in infancy or later in childhood. A decrease in plasma riboflavin levels has been observed in several cases. Recent studies on knockout mice and patient-derived cells have advanced the understanding of these mechanisms. Here, we summarize novel findings on RFVT1-3 and their genetic diseases and discuss their potential as therapeutic drugs.

A 20-year Clinical and Genetic Neuromuscular Cohort Analysis in Lebanon: An International Effort

BACKGROUND

Clinical and molecular data on the occurrence and frequency of inherited neuromuscular disorders (NMD) in the Lebanese population is scarce.

OBJECTIVE

This study aims to provide a retrospective overview of hereditary NMDs based on our clinical consultations in Lebanon.

METHODS

Clinical and molecular data of patients referred to a multi-disciplinary consultation for neuromuscular disorders over a 20-year period (1999-2019) was reviewed.

RESULTS

A total of 506 patients were diagnosed with 62 different disorders encompassing 10 classes of NMDs. 103 variants in 49 genes were identified. In this cohort, 81.4%of patients were diagnosed with motor neuron diseases and muscular dystrophies, with almost half of these described with spinal muscular atrophy (SMA) (40.3%of patients). We estimate a high SMA incidence of 1 in 7,500 births in Lebanon. Duchenne and Becker muscular dystrophy were the second most frequently diagnosed NMDs (17%of patients). The latter disorders were associated with the highest number of variants (39) identified in this study. A highly heterogeneous presentation of Limb Girdle Muscular Dystrophy and Charcot-Marie-Tooth disease was notably identified. The least common disorders (5.5%of patients) involved congenital, metabolic, and mitochondrial myopathies, congenital myasthenic syndromes, and myotonic dystrophies. A review of the literature for selected NMDs in Lebanon is provided.

CONCLUSIONS

Our study indicates a high prevalence and underreporting of heterogeneous forms of NMDs in Lebanon- a major challenge with many novel NMD treatments in the pipeline. This report calls for a regional NMD patient registry.

Brown-Vialetto-Van Laere and Fazio-Londe syndromes: SLC52A3 mutations with puzzling phenotypes and inheritance

BACKGROUND

Brown-Vialetto-Van Laere syndrome (BVVLS) and Fazio-Londe disease (FLD) are rare neurological disorders presenting with pontobulbar palsy, muscle weakness and respiratory insufficiency. Mutations in SLC52A2 (hRFVT-2) or SLC52A3 (hRFVT-3) genes can be responsible for these disorders with an autosomal recessive pattern of inheritance. The aim of this study was to screen for mutations in SLC52A2 and SLC52A3 among Indian families diagnosed with BVVLS and FLD.

METHODS

SLC52A2 and SLC52A3 were screened in one FLD and three BVVLS patients by exon-specific amplification using PCR and sequencing. In silico predictions using bioinformatics tools and confocal imaging using HEK-293 cells were performed to determine the functional impact of identified mutations.

RESULTS

Genetic analysis of a mother and son with BVVLS was identified with a novel homozygous mutation c.710C>T (p.Ala237Val) in SLC52A3. This variant was found to have an autosomal pseudodominant pattern of inheritance, which was neither listed in the Exome Variant Server or in the 1000 Genomes Project database. In silico analysis and confocal imaging of the p.Ala237Val variant showed higher degree of disorderness in hRFVT-3 that could affect riboflavin transport. Furthermore, a common homozygous mutation c.62A>G (p.Asn21Ser) was identified in other BVVLS and FLD patients. Despite having different clinical phenotypes, both BVVLS and FLD can be attributed to this mutation.

CONCLUSION

A rare and peculiar pattern of autosomal pseudodominant inheritance is observed for the first time in two genetically related BVVLS cases with Indian origin and a common mutation c.62A>G (p.Asn21Ser) in SLC52A3 can be responsible for both BVVLS and FLD with variable phenotypes.

Auditory neuropathy in Brown-Vialetto-Van Laere syndrome due to riboflavin transporter RFVT2 deficiency

AIM

Mutations in the genes encoding the riboflavin transporters RFVT2 and RFVT3 have been identified in Brown-Vialetto-Van Laere syndrome, a neurodegenerative disorder characterized by hearing loss and pontobulbar palsy. Treatment with riboflavin has been shown to benefit individuals with the phenotype of RFVT2 deficiency. Understanding the characteristics of hearing loss in riboflavin transporter deficiency would enable early diagnosis and therapy.

METHOD

We performed hearing assessments in seven children (from four families) with RFVT2 deficiency and reviewed results from previous assessments. Assessments were repeated after 12 months and 24 months of riboflavin therapy and after cochlear implantation in one individual.

RESULTS

Hearing loss in these individuals was due to auditory neuropathy spectrum disorder (ANSD). Hearing loss was identified between 3 years and 8 years of age and progressed rapidly. Hearing aids were not beneficial. Riboflavin therapy resulted in improvement of hearing thresholds during the first year of treatment in those with recent-onset hearing loss. Cochlear implantation resulted in a significant improvement in speech perception in one individual.

INTERPRETATION

Riboflavin transporter deficiency should be considered in all children presenting with an auditory neuropathy. Speech perception in children with ANSD due to RFVT2 deficiency may be significantly improved by cochlear implantation.

Auditory neuropathy spectrum disorder with Brown–Vialetto–Van Laere syndrome: challenges in hearing rehabilitation

Background:

Brown–Vialetto–Van Laere syndrome is a rare neurological disorder characterised by pontobulbar palsy and sensorineural hearing loss. Hearing rehabilitation continues to be a challenge because the exact lesion site is unknown.

Case report:

We examined the clinical and audiological profiles of a case series comprising four siblings with Brown–Vialetto–Van Laere syndrome who had decreased hearing and poor speech discrimination. Audiological investigations revealed normal otoacoustic emissions with absent auditory brainstem responses and middle-ear reflexes in sensorineural hearing loss, suggestive of auditory neuropathy spectrum disorder.

Conclusion:

The sensorineural hearing loss in Brown–Vialetto–Van Laere syndrome patients is a retrocochlear pathology resembling auditory neuropathy spectrum disorder, with the lesion being most probably of post-synaptic origin. Early cochlear implantation along with high-dose riboflavin represents a possible rehabilitation therapy. However, further research is needed to confirm this. This report emphasises the need for a thorough neurological evaluation of auditory neuropathy spectrum disorder patients.

Mutations in riboflavin transporter present with severe sensory loss and deafness in childhood

INTRODUCTION

We have identified a large consanguineous Lebanese family with 5 individuals with severe childhood-onset recessive sensory loss associated with deafness and variable optic atrophy.

METHODS

Autozygosity mapping was performed in all affected individuals, followed by whole-exome sequencing (WES) in 2 individuals.

RESULTS

WES identified a homozygous missense mutation (c.916G>A, p.G306R) in the cerebral riboflavin transporter SLC52A2, recently shown to cause Brown-Vialetto-Van-Laere syndrome (BVVLS), which is considered primarily a motor neuronopathy. Our patients have a phenotype distinct from BVVLS, characterized by severe progressive sensory loss mainly affecting vibration and proprioception that evolves to include sensorineural hearing loss in childhood, variable degrees of optic atrophy, and marked upper extremity weakness and atrophy. Treatment of 3 patients with 400 mg/day riboflavin over 3 months produced definite clinical improvement.

CONCLUSIONS

Mutations in SLC52A2 result in a recognizable phenotype distinct from BVVLS. Early recognition of this disorder is critical, given its potential treatability.

Treatable childhood neuronopathy caused by mutations in riboflavin transporter RFVT2

Childhood onset motor neuron diseases or neuronopathies are a clinically heterogeneous group of disorders. A particularly severe subgroup first described in 1894, and subsequently called Brown-Vialetto-Van Laere syndrome, is characterized by progressive pontobulbar palsy, sensorineural hearing loss and respiratory insufficiency. There has been no treatment for this progressive neurodegenerative disorder, which leads to respiratory failure and usually death during childhood. We recently reported the identification of SLC52A2, encoding riboflavin transporter RFVT2, as a new causative gene for Brown-Vialetto-Van Laere syndrome. We used both exome and Sanger sequencing to identify SLC52A2 mutations in patients presenting with cranial neuropathies and sensorimotor neuropathy with or without respiratory insufficiency. We undertook clinical, neurophysiological and biochemical characterization of patients with mutations in SLC52A2, functionally analysed the most prevalent mutations and initiated a regimen of high-dose oral riboflavin. We identified 18 patients from 13 families with compound heterozygous or homozygous mutations in SLC52A2. Affected individuals share a core phenotype of rapidly progressive axonal sensorimotor neuropathy (manifesting with sensory ataxia, severe weakness of the upper limbs and axial muscles with distinctly preserved strength of the lower limbs), hearing loss, optic atrophy and respiratory insufficiency. We demonstrate that SLC52A2 mutations cause reduced riboflavin uptake and reduced riboflavin transporter protein expression, and we report the response to high-dose oral riboflavin therapy in patients with SLC52A2 mutations, including significant and sustained clinical and biochemical improvements in two patients and preliminary clinical response data in 13 patients with associated biochemical improvements in 10 patients. The clinical and biochemical responses of this SLC52A2-specific cohort suggest that riboflavin supplementation can ameliorate the progression of this neurodegenerative condition, particularly when initiated soon after the onset of symptoms.

Madras motor neuron disease (MMND) is distinct from the riboflavin transporter genetic defects that cause Brown-Vialetto-Van Laere syndrome

Introduction

Madras motor neuron disease (MMND), MMND variant (MMNDV) and Familial MMND (FMMND) have a unique geographic distribution predominantly reported from Southern India. The characteristic features are onset in young, weakness and wasting of limbs, multiple lower cranial nerve palsies and sensorineural hearing loss. There is a considerable overlap in the phenotype of MMND with Brown–Vialetto–Van Laere syndrome (BVVL) Boltshauser syndrome, Nathalie syndrome and Fazio–Londe syndrome. Recently a number of BVVL cases and families have been described with mutations in two riboflavin transporter genes SLC52A2 and SLC52A3 (solute carrier family 52, riboflavin transporter, member 2 and 3 respectively).

Methods and results

We describe six families and four sporadic MMND cases that have been clinically characterized in detail with history, examination, imaging and electrophysiological investigations. We sequenced the SLC52A1, SLC52A2 and SLC52A3 in affected probands and sporadic individuals from the MMND series as well as the C9ORF72 expansion. No genetic defects were identified and the C9ORF72 repeats were all less than 10.

Conclusions

These data suggest that MMND is a distinct clinical subgroup of childhood onset MND patients where the known genetic defects are so far negative. The clinico-genetic features of MMND in comparison with the BVVL group of childhood motor neuron diseases suggest that these diseases are likely to share a common defective biological pathway that may be a combination of genetic and environmental factors.

The Brown-Vialetto-Van Laere and Fazio Londe syndrome revisited: natural history, genetics, treatment and future perspectives

The Brown-Vialetto-Van Laere syndrome is a rare neurological disorder which may present at all ages with sensorineural deafness, bulbar palsy and respiratory compromise. Fazio-Londe syndrome is considered to be the same disease entity. Recently it was demonstrated that in some patients the disease is caused by mutations in the SLC52A3 gene which encodes the intestinal (hRFT2) riboflavin transporter. In these patients riboflavin deficiency is the cause of the BVVL/FL syndrome and supplementation of riboflavin proved a life saving treatment. Mutations in the SLC52A2 gene and the SLC52A1 (GPR172B) gene, coding for human riboflavin transporters hRFT3 and hRFT1 have been associated with the BVVL syndrome as well. We performed a review of the literature, with emphasis on the natural history and the effects of treatment in these patients. A total of 35 publications were traced reporting on the clinical presentation of 74 patients who presented before age 18. The most prevalent symptoms were bulbar palsy, hearing loss, facial weakness and respiratory compromise. Death was reported in 28 of the 61 untreated patients, with a very low survival in patients presenting before age 4. All 13 patients who were treated with riboflavin survived, with a strong clinical improvement after days to months of treatment in eight patients. Three patients demonstrated a stable clinical course and treatment was stopped early in two patients. Abnormalities in plasma flavin levels and/or plasma acylcarnitine profiles were observed in some but not in all patients, and also patients with normal plasma flavin levels and acylcarnitine profiles demonstrated a striking clinical improvement on riboflavin supplementation. It is now clear that proper diagnosis requires mutation analysis of all three transporter genes and treatment should be started immediately without first awaiting results of molecular analysis. Clinical improvement may be rapid or gradual over a period of more than 12 months.

Association of UBQLN1 mutation with Brown-Vialetto-Van Laere syndrome but not typical ALS

Genetic variants in UBQLN1 gene have been linked to neurodegeneration and mutations in UBQLN2 have recently been identified as a rare cause of amyotrophic lateral sclerosis (ALS).

OBJECTIVE

To test if genetic variants in UBQLN1 are involved in ALS.

METHODS

102 and 94 unrelated patients with familial and sporadic forms of ALS were screened for UBQLN1 gene mutations. Single nucleotide variants were further screened in a larger set of sporadic ALS (SALS) patients and unrelated control subjects using high-throughput Taqman genotyping; variants were further assessed for novelty using the 1000Genomes and NHLBI databases. In vitro studies tested the effect of UBQLN1 variants on the ubiquitin-proteasome system (UPS).

RESULTS

Only two UBQLN1 coding variants were detected in the familial and sporadic ALS DNA set; one, the missense mutation p.E54D, was identified in a single patient with atypical motor neuron disease consistent with Brown-Vialetto-Van Laere syndrome (BVVLS), for whom c20orf54 mutations had been excluded. Functional studies revealed that UBQLN1E54D protein forms cytosolic aggregates that contain mislocalized TDP-43 and impairs degradation of ubiquitinated proteins through the proteasome.

CONCLUSIONS

Genetic variants in UBQLN1 are not commonly associated with ALS. A novel UBQLN1 mutation (E45D) detected in a patient with BVVLS altered nuclear TDP-43 localization in vitro, suggesting that UPS dysfunction may also underlie the pathogenesis of this condition.

Exome sequencing reveals riboflavin transporter mutations as a cause of motor neuron disease

Brown-Vialetto-Van Laere syndrome was first described in 1894 as a rare neurodegenerative disorder characterized by progressive sensorineural deafness in combination with childhood amyotrophic lateral sclerosis. Mutations in the gene, SLC52A3 (formerly C20orf54), one of three known riboflavin transporter genes, have recently been shown to underlie a number of severe cases of Brown-Vialetto-Van Laere syndrome; however, cases and families with this disease exist that do not appear to be caused by SLC52A3 mutations. We used a combination of linkage and exome sequencing to identify the disease causing mutation in an extended Lebanese Brown-Vialetto-Van Laere kindred, whose affected members were negative for SLC52A3 mutations. We identified a novel mutation in a second member of the riboflavin transporter gene family (gene symbol: SLC52A2) as the cause of disease in this family. The same mutation was identified in one additional subject, from 44 screened. Within this group of 44 patients, we also identified two additional cases with SLC52A3 mutations, but none with mutations in the remaining member of this gene family, SLC52A1. We believe this strongly supports the notion that defective riboflavin transport plays an important role in Brown-Vialetto-Van Laere syndrome. Initial work has indicated that patients with SLC52A3 defects respond to riboflavin treatment clinically and biochemically. Clearly, this makes an excellent candidate therapy for the SLC52A2 mutation-positive patients identified here. Initial riboflavin treatment of one of these patients shows promising results.

Brown-Vialetto-Van Laere syndrome: a riboflavin-unresponsive patient with a novel mutation in the C20orf54 gene

Brown-Vialetto-Van Laere syndrome (Online Mendelian Inheritance in Man number 211530) is a neurodegenerative disorder characterized by pontobulbar palsy affecting cranial nerves (mainly VII-XII). Sensorineural deafness is often the leading sign, followed by other neurologic signs. Inheritance is often autosomal recessive, with mutations in the C20orf54 gene (Online Mendelian Inheritance in Man number 613350). Three previous patients with mutations in the C20orf54 gene and clinical signs of Brown-Vialetto-Van Laere or Fazio-Londe syndrome revealed a metabolic profile suggesting a multiple acyl-coenzyme A dehydrogenase defect. They benefited from riboflavin. We describe a 3-year-old girl with early-onset Brown-Vialetto-Van Laere syndrome and a novel mutation in the C20orf54 gene (c.989G>T). On T(2)-weighted imaging, increased signal intensity of the vestibular nuclei bilaterally, the pedunculus cerebellaris superior and the central tegmental tract were observed during acute clinical deterioration. Her metabolic profile was normal. Trials with steroids, immunoglobulins, and riboflavin produced no effect. The patient recovered slowly during subsequent months, with residual deficits. Brown-Vialetto-Van Laere syndrome should be considered in patients with sensorineural hearing loss and pontobulbar palsy. Patients should be screened for riboflavin deficiency and a therapy with riboflavin may provide effective treatment in some affected patients.

Cochlear Implantation in Brown-Vialetto-Van-Laere syndrome

OBJECTIVE

To report outcomes for the first known cochlear implantation procedures in two patients with Brown-Vialetto-Van-Laere syndrome.

PATIENTS

Two adult patients (a brother and sister) with post-lingual sensorineural deafness associated with Brown-Vialetto-Van-Laere syndrome. The female patient presented with a milder form of the syndrome.

INTERVENTION

Cochlear implantation.

MAIN OUTCOME MEASURE

Post-implantation speech discrimination scores.

RESULTS

Auditory evoked potential testing suggested pathological changes in both patients' cochleae, auditory nerves, brainstem and (probably) central auditory pathways. In the male patient, despite implantation of the better ear, the Bamford-Kowal-Bench sentence score was zero at 21 months post-implantation. In the female patient, Bamford-Kowal-Bench sentence scores at six months post-implantation were 25 per cent in quiet and 3 per cent in noise.

CONCLUSION

These poor clinical outcomes appear to be related to retrocochlear and probable central auditory pathway degeneration.

Brown-Vialetto-Van Laere syndrome, a ponto-bulbar palsy with deafness, is caused by mutations in c20orf54

Brown-Vialetto-Van Laere syndrome is a rare neurological disorder with a variable age at onset and clinical course. The key features are progressive ponto-bulbar palsy and bilateral sensorineural deafness. A complex neurological phenotype with a mixed picture of upper and lower motor neuron involvement reminiscent of amyotrophic lateral sclerosis evolves with disease progression. We identified a candidate gene, C20orf54, by studying a consanguineous family with multiple affected individuals and subsequently demonstrated that mutations in this gene were the cause of disease in other, unrelated families.

Brown-Vialetto-Van Laere syndrome

The Brown-Vialetto-Van Laere syndrome (BVVL) is a rare neurological disorder characterized by progressive pontobulbar palsy associated with sensorineural deafness. Fifty-eight cases have been reported in just over 100 years. The female to male ratio is approximately 3:1. The age of onset of the initial symptom varies from infancy to the third decade. The syndrome most frequently presents with sensorineural deafness, which is usually progressive and severe. Lower cranial nerve involvement and lower and upper motor neuron limb signs are common neurological features. Other features include respiratory compromise (the most frequent non-neurological finding), limb weakness, slurring of speech, facial weakness, and neck and shoulder weakness. Optic atrophy, retinitis pigmentosa, macular hyperpigmentation, autonomic dysfunction, epilepsy may occur. The etiopathogenesis of the condition remains elusive. Approximately 50% of cases are familial, of which autosomal recessive is suggested. The remaining cases are sporadic. The diagnosis is usually based on the clinical presentation. Investigations (neurophysiological studies, magnetic resonance imaging of the brain, muscle biopsy, cerebrospinal fluid examination) are done to exclude other causes or to confirm the clinical findings. The differential diagnoses include the Fazio-Londe syndrome, amyotrophic lateral sclerosis, Nathalie syndrome, Boltshauser syndrome and Madras motor neuron disease. Treatment with steroids or intravenous immunoglobulin may result in temporary stabilization of the syndrome. However, the mainstays of management are supportive and symptomatic treatment, in particular assisted ventilation and maintenance of nutrition via gastrostomy. The clinical course of BVVL is variable and includes gradual deterioration (almost half of cases), gradual deterioration with stable periods in between (a third of cases) and deterioration with abrupt periods of worsening (just under a fifth of cases). After the initial presentation, one third of patients survive for ten years or longer.

Madras motor neuron disease (MMND): clinical description and survival pattern of 116 patients from Southern India seen over 36 years (1971-2007)

Madras motor neuron disease (MMND), MMND variant (MMNDV) and Familial MMND (FMMND) have a unique geographic distribution predominantly reported from Southern India. The characteristic features are onset in young, weakness and wasting of limbs, multiple lower cranial nerve palsies and sensorineural hearing loss. We describe the clinical features and survival pattern in 116 patients with Sporadic MMND, MMND variant and FMMND. A retrospective review of patients' medical records for clinical manifestations, electromyography, imaging, audiological and histopathology findings was performed. Over 36 years (1971 to 2007) 116 patients (men: 59; women: 57) particularly hailing from Southern India were seen. Mean age of onset was 15.8+/-7.9 years. Predominant initial manifestations were impaired hearing with wasting and weakness of distal limb muscles and pyramidal dysfunction. All patients had clinical and/or audiological evidence of hearing impairment. Patients with MMNDV in addition had optic atrophy. The overall mean survival duration was 334.9+/-27.9 months. Thus, Madras motor neuron disease is clinically a distinct entity with features of amyotrophic lateral sclerosis but with young age of onset and presence of auditory neuropathy. Studies to look for environmental and genetic basis of this intriguing disease are necessary to find the causation of this rare disorder.

Severe sleep-disordered breathing in a patient with Brown–Vialetto–Van Laere syndrome: Polysomnographic findings

Brown-Vialetto-Van Laere (BVVL) syndrome is a rare disorder with clinical features that include progressive bilateral sensorineural deafness and a variety of cranial nerve impairments. Respiratory compromise has been observed in most familial and sporadic cases; however, few studies have been published regarding sleep-disordered breathing in this syndrome. We report the unique case of a 16-year-old girl with the clinical features of BVVL syndrome who presented with bilateral sensorineural hearing loss and then progressively developed paralysis of the 7th and 9th-12th cranial nerves. More importantly, she presented with the unusual feature of severe sleep-disordered breathing. A polysomnographic study showed evidence of dominant central sleep apnea, and the majority of apneic episodes more likely occurred in stage 2 during NREM sleep. The central sleep apnea was associated with rapid respiratory deterioration and death. This report raises the fact that a patient with BVVL syndrome may present with severe sleep-disordered breathing as a life-threatening condition, which emphasizes the need for greater attention to the early detection of potential sleep-disordered breathing in these afflicted with the BVVL syndrome for optimal clinical management.

A Brazilian family with Brown-Vialetto-van Laere syndrome with autosomal recessive inheritance

We report the first Brazilian family with Brown-Vialetto-van Laere syndrome. The presence of consanguineous marriages and illness affecting three sisters and one niece support an autosomal recessive transmission. The age at onset of the illness ranged from 12 to 20 years old. The time interval between hearing loss and involvement of other cranial nerves varied from 3 to 12 years. MRI demonstrated bulbar atrophy and also high intensity signal at T2 weighted and fluid attenuated inversion recovery (FLAIR) sequences.

Familial Madras motor neuron disease (FMMND): study of 15 families from southern India

Madras motor neuron disease (MMND) and Madras motor neuron disease variant (MMNDV) have an unique geographic distribution with concentration of majority of cases in the southern states of India. They have the characteristic features of onset in young, weakness and wasting of the limbs, multiple cranial nerve palsies particularly involving the 7th, 9th to 12th and sensorineural hearing impairment. In addition, all patients with MMNDV have bilateral optic atrophy. During the past 32 years, a total of 104 patients were diagnosed to have MMND and among these 25 patients with the familial form were further evaluated. In this report, we describe the clinical features of these 25 patients diagnosed to have familial Madras motor neuron disease (FMMND) or familial Madras motor neuron disease variant (FMMNDV), belonging to 15 families hailing from southern India. There were 10 patients diagnosed to have FMMND and 15 with FMMNDV. There were 14 males and 11 females with mean age at onset of 13.0+/-6.2 years and mean duration of illness of 73.6+/-74.0 months. Notably, the occurrence of MMNDV in the familial group (15 of 25 patients) was significantly more as compared to occurrence in the group with sporadic MMND (SMMND) [12 of 79 patients] (p=0.0002).

Pontobulbar palsy and neurosensory deafness (Brown-Vialetto-van Laere syndrome) with hyperintense brainstem nuclei on magnetic resonance imaging: new finding in three siblings

Three siblings (one boy and two girls) with Brown-Vialetto-van Laere syndrome are reported. A peculiar feature of onset with hearing loss in a patient with multiple cranial nerve palsies and a positive family history suggests this diagnosis. In our family, an autosomal recessive mode of inheritance was seen. In addition, we observed that early onset was associated with rapid deterioration and death. Optic nerve involvement and hyperintensity of the brainstem nuclei on magnetic resonance imaging (MRI) are two new features described in this report.

Clinical features and neurophysiological follow-up in a case of Brown-Vialetto-Van Laere syndrome

Brown-Vialetto-Van Laere syndrome is a rare disease of unknown origin commonly considered as part of the large group of motor neuron diseases. The course is quite variable: it may be quickly fatal or protracted, with relapsing phases followed by periods of arrest and even partial improvement. We describe a case of Brown-Vialetto-Van Laere syndrome with strong family history for sensorineural hearing impairment. The patient came to our medical attention for severe respiratory failure and leg weakness. The clinical conditions partially improved with recovery of spontaneous respiration and mild increase in muscle strength. The neurophysiological studies performed on our patient showed evidence of nerve damage with subsequent improvement. Our study raises the possibility that the disorder is due to primary nerve damage, which can better justify the intermittent course of the disease, the partial clinical regression and the neurophysiological improvement, never detected in typical motor neuron disorders.

Brown-Vialetto-Van Laere syndrome; variability in age at onset and disease progression highlighting the phenotypic overlap with Fazio-Londe disease

We report four siblings showing features of a pontobulbar palsy, a mixed spinal and upper motor neuropathy and variable deafness. The observation of affected males and females born to consanguineous first cousin parents suggests autosomal recessive inheritance. Two children presented in the first 16 months of life with stridor and died of respiratory failure by the age of 2 years. Hearing loss was not apparent in these infants. In contrast, 2 further siblings developed a bulbar palsy in their sixth year followed by the onset of deafness and features of an anterior horn neuropathy with corticospinal tract involvement. They exhibited a relatively slow but relentless decline over a period of several years. These cases highlight the phenotypic overlap of Brown-Vialetto-Van Laere syndrome with Fazio-Londe disease. Rather than representing two separate disorders, our findings suggest the possibility of a single disease entity which may usefully be considered a form of juvenile amyotrophic lateral sclerosis.

Vialetto-Van Laere syndrome in two sisters born to consanguineous parents

Vialetto-Van Laere syndrome is a rare anterior horn cell disease affecting young persons. Bulbar palsy with deafness is the characteristic feature. Of the total 35 cases reported in the literature, only one case was from India. This article presents the second case report from India.

Madras motor neuron disease variant, clinical features of seven patients

Madras motor neuron disease (MMND) has the characteristic features of onset in the young, atrophy and weakness of the limbs, multiple cranial nerve palsies particularly the seventh, ninth to twelfth and sensorineural hearing loss with unique geographic distribution to southern part of India. During a period of 28 years (1974-2001), 7 (13%) among 54 patients of MMND seen at a tertiary referral center at Bangalore, India, had the additional features of optic atrophy in all and cerebellar involvement in three of them. There were three males and four females, the mean age at onset was 11.7 years, with a mean duration of illness of 6.4 years. All except one patient were ambulant and independent in the activities of daily living. Family history of MMND was present in more than a quarter (28.6%) of patients. Compared to MMND, these patients had onset of illness at a younger age and family history was more frequently observed, however, these differences were not statistically significant. Bulbar palsy was an invariable feature, being present in all patients compared to 38.3% of MMND and the difference was statistically significant (p=0.003). This clinical profile may be considered to be a variant of Madras motor neuron disease (MMNDV).

Infantile progressive bulbar palsy with deafness

A 12-month-old boy with progressive cranial nerve palsies followed by ventilatory failure demanding artificial ventilation, generalized muscle weakness, and rapid progression to death at the age of 21 months is described. The patient had normal early development and also apparently normal hearing at presentation of illness but, after 6 months of the onset of the disease, hearing loss was documented by brainstem auditory evoked potentials (BAEP). Although the initial clinical and laboratory findings of this infant could fit with the diagnosis of progressive childhood bulbar palsy or Fazio-Londe (FL) disease, the subsequent appearance of hearing loss suggests that this patient represents a case of progressive bulbar palsy with perceptive deafness or Brown-Vialetto-Van Laere (BVVL) syndrome. To our knowledge, this case of BVVL syndrome with severe clinical features and rapid deterioration leading to death is the youngest one reported in the literature. Furthermore, this case emphasizes the need for repeated auditory examinations, including the performance of BAEP in all cases, especially infants and young children with progressive bulbar palsy.