LXI The Factor of Heredity in Labyrinthine Deafness and Paroxysmal Vertigo (Ménière's Syndrome)

Clinical Subgroups in Bilateral Meniere Disease

Meniere disease (MD) is a heterogeneous clinical condition characterized by sensorineural hearing loss, episodic vestibular symptoms, and tinnitus associated with several comorbidities, such as migraine or autoimmune disorders (AD). The frequency of bilateral involvement may range from 5 to 50%, and it depends on the duration of the disease. We have performed a two-step cluster analysis in 398 patients with bilateral MD (BMD) to identify the best predictors to define clinical subgroups with a potential different etiology to improve the phenotyping of BMD and to develop new treatments. We have defined five clinical variants in BMD. Group 1 is the most frequently found, includes 46% of patients, and is defined by metachronic hearing loss without migraine and without AD. Group 2 is found in 17% of patients, and it is defined by synchronic hearing loss without migraine or AD. Group 3, with 13% of patients, is characterized by familial MD, while group 4, that includes 12% of patients, is associated by the presence of migraine in all cases. Group 5 is found in 11% of patients and is defined by AD. This approach can be helpful in selecting patients for genetic and clinical research. However, further studies will be required to improve the phenotyping in these clinical variants for a better understanding of the diverse etiological factors contributing to BMD.

Familial Ménière's disease: clinical and genetic aspects

Background and purpose:

Ménière's disease is not uncommon, with an incidence in Caucasians of about one in 2000. The incidence peaks in the fifth decade. Cases are usually isolated or sporadic, but in perhaps five per cent other family members are affected. We report here the clinical and genetic characteristics of a comprehensive set of familial Ménière's disease cases from the UK.

Methods:

Forty-six affected families were studied. All cases were diagnosed using the American Academy of Otolaryngology–Head and Neck Surgery committee on hearing and equilibrium 1995, or more stringent, criteria.

Outcomes and results:

Autosomal dominant inheritance with reduced penetrance was the most likely mode of inheritance overall. Apparent genetic anticipation was observed, but may also be a result of ascertainment bias given the collection strategy. There was also a slight tendency for cases to result from maternal transmission within the families in this set. The family pedigrees are presented, and the authors have also set up a website at which all the pedigrees may be viewed in greater detail.

Migraine associated vertigo

The interrelations of migraine and vertigo are complex, eluding a simple localization either centrally or peripherally. Spontaneous episodic vertigo, benign paroxysmal positional vertigo, and Meniere's disease all occur more frequently in patients with migraine than in those without. Family studies support a hereditary predisposition to migraine associated vertigo. In this review, we discuss definitions, epidemiology, associated syndromes, neurootological abnormalities, genetics and treatment for patients with migraine and vertigo.

Familial Ménière's disease in five generations

OBJECTIVE

Clinical characterization of a Swedish family followed for five generations. Several members of each generation had Ménière's disease (MD). Possible modes of genetic transmission were assessed.

STUDY DESIGN

Retrospective family survey.

SETTING

University hospital. Tertiary referral center.

PATIENTS

Members of a large family in which several members in each generation were affected by MD.

INTERVENTIONS

Hearing levels were assessed, and the patients were asked to complete a questionnaire regarding age at onset, hearing loss, tinnitus, aural fullness, vertigo, and if MD was unilateral or bilateral. Glycerol tests were performed in a few cases. For deceased relatives, information was obtained from patient charts and interviews with relatives. Genetic studies with linkage analysis was performed for the loci DFNA 1, DFNA6/14, DFNA9, and DFNA15.

RESULTS

One member of Generation I and, according to patient charts, two members of Generation II could have suffered from MD. In Generations III to V, 9 of 25 members developed inner ear dysfunction. Six of these individuals developed MD that was strictly in accordance with American Academy of Otolaryngology and Head and Neck Surgery, 1995 guidelines criteria, whereas three individuals had unilateral or bilateral hearing impairment, one in combination with benign paroxysmal positioning vertigo, which could represent an incomplete expression of the disease. The mean age at disease onset was 64.5 years in Generation III, 43 years in Generation IV, and 25 years in Generation V. In the genetic studies, none of the regions investigated showed linkage to the disease gene with a significant calculated log of odds ratio (LOD) score above three.

CONCLUSION

The pattern of inheritance suggested that familial MD was autosomal dominant and exhibited incomplete expression of inner ear symptoms in some affected members. The decreasing age at onset of disease with succeeding generations could indicate anticipation. None of the hitherto-known DFNA loci, which has phenotypes bearing some resemblance to MD, had haplotypes in common with this large family affected by MD.

HUMANNONSYNDROMICSENSORINEURALDEAFNESS

Given the unique biological requirements of sound transduction and the selective advantage conferred upon a species capable of sensitive sound detection, it is not surprising that up to 1% of the approximately 30,000 or more human genes are necessary for hearing. There are hundreds of monogenic disorders for which hearing loss is one manifestation of a syndrome or the only disorder and therefore is nonsyndromic. Herein we review the supporting evidence for identifying over 30 genes for dominantly and recessively inherited, nonsyndromic, sensorineural deafness. The state of knowledge concerning their biological roles is discussed in the context of the controversies within an evolving understanding of the intricate molecular machinery of the inner ear.

Genetics (molecular biology) and Meniere's disease

COCH is not the FMD gene detected in our linkage study; furthermore, COCH and FMD are not allelic. The indications are that FMD is heterogenetic. The linkage analysis points to the possibility of one FMD mutation in one of the neighboring candidate genes on chromosome 14, and, with anticipation, possibly a triple repeat amplification. Recently, the myotonic dystrophy type 2 locus has been shown to contain an expanded tetranucleotide repeat [46], so the search for a similar repeat on 14q is indicated.

Occurrence of familial Meniere's syndrome and migraine in Brasília

Since 1941, many families with several members affected by Meniere's syndrome have been described. "Migraine-like" headache was always mentioned. In 1997, we described a large family with Meniere's syndrome and migraine, both transmitted in an autosomal dominant mode. Recently, a gene that could be responsible for Meniere's symptoms has been identified. However, the incidence of familial Meniere's syndrome is still unknown. A. W. Morrison et al estimated this incidence as between 2.9% and 12%. During the years 1997 and 1998, we saw 8 new patients with typical Meniere's syndrome in our outpatient department. They were referred to Dr Messias, who did a careful search for other affected family members. Six of them had relatives with Meniere's syndrome and migraine transmitted in an autosomal dominant mode. The familial incidence of Meniere's syndrome and migraine in Brasília seems to be higher than the figures of Morrison et al for the United Kingdom. The 6 families are described herein.

Menière's syndrome and migraine: incidence in one family

Since 1992, we have applied a standard questionnaire to all our Meniere's syndrome patients. We ask about other family members affected by the symptoms and about the presence of the usual migraine symptom. Through this questionnaire we have identified a family that has some members affected by Meniere's syndrome alone, some others with associated migraine, and still others with migraine alone. Two members of this family started out with migraine and later in life developed Meniere's syndrome. The genetic transmission follows an autosomal dominant pattern for both Meniere's syndrome and migraine. We have interviewed and studied 19 affected persons from several generations of this family, who form the basis of this report. The possibility of a common autosomal dominant genetic determinant for Meniere's syndrome and migraine and its implications for the causation of Meniere's disease are discussed.

Meniere's syndrome inherited as an autosomal dominant trait

Brown in 1941 reported on five families having two members with Meniere's syndrome. In 1949 she reported on three siblings (children of first cousins) and two identical twins bearing the syndrome. Bernstein in 1965 reported on seven families having two or more members afflicted by the symptoms. All these reports showed association between Meniere's syndrome and migraine headaches. None provided detailed pedigree studies in order to clarify the mode of genetic transmission. We report on a father, three daughters, and one son with typical Meniere's syndrome and paroxysmal headaches. The pedigree strongly suggests autosomal dominant transmission. After studying this family we have been paying close attention to family histories of Meniere's syndrome patients. It is not at all uncommon to hear about other members of the family with the syndrome, but it is difficult to document all of the cases for logistical reasons.

Bobbing oscillopsia from gentamicin toxicity

A series of 15 patients had been studied, all of whom suffered severe labyrinthine damage from gentamicin. All subjects were patients in a renal unit and had been in renal failure. The antibiotic was administered, either intramuscularly, intravenously or into the dialysate. In most of the patients there was a history of previous or simultaneous administration of another ototoxic agent, either another aminoglycoside, or a loop diuretic. None of the patients developed severe vertigo. They consistently complained, when they eventually were able to get out of bed, a vertical bouncing of their surroundings, when they walked, coinciding with each step. This sensation is made worse if the patient runs, or drives on a bumpy road, and stops as soon as the patient stands still. Caloric tests revealed non-functioning labyrinths on both sides. Gradual improvement in the symptom occurred over a period of months. No cochleotoxic effect was observed. The probable mechanism of this phenomenon is discussed.