Cochlear Implantation in Siblings With Refsum's Disease.

OBJECTIVES: Whether the origin of severe hearing loss in Refsum's syndrome is caused by cochlear impairment or retrocochlear degeneration remains unclear. This case report aims to investigate hearing performance before and after cochlear implantation to shed light on this question. Also, identification of new mutations causing Refsum's syndrome would be helpful in generating additional means of diagnosis. METHODS: A family of 4 individuals was subjected to genetic testing. Two siblings (56 and 61 years old) suffered from severe hearing and vision loss and received bilateral cochlear implants. Genetic analysis, audiological outcome, and clinical examinations were performed. RESULTS: One new mutation in the PHYH gene (c.768del63bp) causing Refsum's disease was found. Preoperative distortion product otoacoustic emissions (DPAOEs) were absent. Postoperative speech perception in Freiburger speech test was 100% for bisyllabic words and 85% (patient No. 1) and 65% (patient No. 2), respectively, for monosyllabic words. Five years after implantation, speech perception remained stable for bisyllabic words but showed decreasing capabilities for monosyllabic words. DISCUSSION: A new mutation causing Refsum's disease is presented. Cochlear implantation in case of severe hearing loss leads to an improvement in speech perception and should be recommended for patients with Refsum's disease, especially when the hearing loss is combined with a severe loss of vision. Decrease of speech perception in the long-term follow-up could indicate an additional retrocochlear degeneration.

Ocular manifestations of genetic skin disorders.

Genetic skin diseases, or genodermatoses, often have extracutaneous manifestations. Ocular manifestations in particular can have significant clinical implications, like blindness. Other manifestations, such as the corneal opacities that occur in X-linked ichthyosis, are asymptomatic but characteristic of a particular genodermatosis. Ophthalmologic examination can aid in diagnosis when characteristic findings are seen. The genodermatoses with ocular manifestations will be reviewed, but neurocutaneous, syndromes, genetic pigmentary disorders, and genetic metabolic diseases are not included because they are covered elsewhere in this issue.

Refsum's disease and cochlear implantation.

OBJECTIVES: The objective was to describe a case of bilateral cochlear implantation in a 59-year-old man with hearing and visual impairment due to Refsum's disease. METHOD: A retrospective case review was performed. RESULTS: After cochlear implantation, the patient demonstrated much improved audiometric performance and reported improved sound localization. CONCLUSIONS: Bilateral cochlear implantation is an important strategy in the improvement of hearing and quality of life in individuals with Refsum's disease.

A child with night blindness: preventing serious symptoms of Refsum disease.

Refsum disease is a genetic progressive neurological disorder caused by neurotoxic phytanic acid, a nutritional component patients are unable to metabolize. Symptoms include retinopathy, polyneuropathy, ataxia, and deafness. They are variable and rarely recognized before adulthood. The authors report the case of a 14-year-old girl diagnosed because of night blindness. They treated her with a phytanic acid-poor diet and extracorporeal lipid apheresis. They used different methods over a 30-month period. Thereafter, the patient was treated with diet only. Membrane filtration and heparin-induced extracorporeal low-density lipoprotein precipitation apheresis were well tolerated. Withdrawal of phytanic acid was studied quantitatively. During a 5-year period, blood phytanic acid levels decreased to a noncritical range. The patient remained free of ophthalmological and neurological progression for a total observation of 12 years. Early diagnosis and effective measures to keep the phytanic acid load low can probably prevent the serious sequelae of Refsum disease. Developing a method for newborn screening is desirable.

Cochlear implantation in Refsum's disease.

Refsum's disease is a rare disorder characterized by accumulation of phytanic acid in plasma and tissues. The main clinical features are retinitis pigmentosa, cerebellar ataxia and chronic polyneuropathy. Sensorineural hearing loss of varying severity can be an additional feature. This study reports our experience with two patients with Refsum's disease who underwent successful cochlear implantation. Both patients had good audiological outcomes after implantation and were overall very satisfied. Bilateral implantation should be considered with patients with severe dual sensory loss. One patient was implanted bilaterally the other unilaterally, primarily due to prolonged duration of unaided unilateral profound hearing loss.

Refsum disease due to the splice-site mutation c.135-2A>G before exon 3 of the PHYH gene, diagnosed eight years after detection of retinitis pigmentosa.

OBJECTIVES: If Refsum disease (RD) is not considered as a differential at onset of the initial manifestations the diagnosis of RD remains unrecognized for a long time as in the following case. CASE REPORT: A 55-y old Caucasian female with hyperextensible joints developed progressive visual impairment due to retinitis pigmentosa and sensorimotor polyneuropathy of the lower limbs since age 32 y. Screening for causes of polyneuropathy at age 40 y revealed markedly elevated serum phytanic acid (PA) with a maximum value of 293.6 microg/ml (n:<6 microg/ml) why RD was diagnosed. Since age 48 y slowly progressive hypacusis was noted. RD was caused by the known transition A135G in exon 3 of the PHYH gene. Additionally, the polymorphism T153C in exon 3 of the PHYH gene was detected. Upon strict adherence to the Chelsea diet PA levels slightly decreased since onset of this therapy. CONCLUSION: This case confirms that RD remains unrecognized for a long time if RD is not considered as a differential of retinitis pigmentosa as the initial manifestation of the disease. Early recognition of RD is important since there is the therapeutic option of starting a diet.

Enfermedades metabólicas de aparición en la edad adulta / Adult-onset metabolic diseases

Los errores congénitos del metabolismo (ECM)pueden debutar en la adolescencia y en la edad adulta.Aunque es difícil aportar datos exactos de prevalenciaya que existen escasos estudios al respecto, inclusoconsiderándolos poco frecuentes, la importancia de sudetección radica en las posibilidades terapéuticas y deconsejo genético familiar.La principal sintomatología de los ECMdel adulto esla neurológica, seguida de la hepática. Se puede establecerdos modos básicos de debut. Uno es el agudo, normalmenteen forma de alteración del nivel de conciencia,letargia, coma de etiología desconocida en un pacientepreviamente sano (déficits del ciclo de la urea, trastornosde la remetilación de la homocisteína y porfirias sonaquí las causas más frecuentes). Por otra parte está lasintomatología crónica, insidiosa, a menudo progresiva,en la que suele haber cuadros clínicos complejos, y másraramente un síntoma aislado de manera persistente (laenfermedad de Wilson, enfermedades mitocondriales,lisosomales, la enfermedad de Refsumy las glucogenosisson algunos ejemplos en este grupo).Es de especial importancia conocer las formas dedebut agudo, que suelen ser situaciones de extremaurgencia, en las que una conducta adecuada puede evitarel fallecimiento del paciente. En este caso, exámenessencillos de laboratorio como la determinación del amonio,homocisteína, lactato, acilcarnitinas, aminoácidos,ácidos orgánicos y porfirinas, pueden orientar el diagnósticoy permiten iniciar un tratamiento intensivo.En este capítulo se pretende realizar un enfoquepráctico, abordando las características generales y clavesclínicas de sospecha de los ECM más habituales enel adulto

Inborn errors of metabolism (IEM) can have theironset in adolescence or in adulthood. Although it isdifficult to contribute exact data on prevalence–because there are few studies in this respect, and IEMare regarded as infrequent– their detection is importantdue to the possibilities for therapy and family geneticcounselling.The main symptoms of IEM in the adult areneurological, followed by hepatic. Two basic modes ofonset can be established. One is acute, normally takingthe form of consciousness alteration, lethargy, coma ofunknown etiology in a previously healthy patient (ureacycle deficits, homocysteine remethylation disordersand porphyries are the most frequent causes). Theother is an insidious, often progressive, chronicsymptomathology that can involve complex clinicalfeatures, and more rarely a symptom that is isolated ina persistent way (Wilson’s disease, mitochondrialdiseases, lysosomal storage disorders, Refsum’sdisease and glycogenosis are some examples of thisgroup).It is especially important to determine the forms ofacute onset as these can present situations of extremeemergency where appropriate conduct can prevent thedeath of the patient. In this case, simple laboratoryexaminations, such as determination of ammonia,homocysteine, lactate, acylcarnitines, amino acids,organic and porfirines, can guide the diagnosis andenable the start of intensive treatment.This article provides a practical approach thatdeals with the general characteristics and the clinicalkeys for suspecting the most usual IEMs in the adult

Smell testing: an additional tool for identification of adult Refsum's disease.

BACKGROUND: Adult Refsum's disease (ARD) is characterised by the presence of retinitis pigmentosa, ataxia, deafness, sensory neuropathy, and bony changes. The diagnosis is confirmed by the presence of phytanic acidaemia. Although reduced smell function has been described in ARD, its value in the diagnosis of the condition has not been fully evaluated. OBJECTIVE: To investigate the prevalence and degree of olfactory dysfunction in patients with ARD. METHOD: The olfactory function of 16 patients with ARD was assessed using the quantitative University of Pennsylvania Smell Identification Test (UPSIT). RESULTS: All patients had complete anosmia or grossly impaired smell function with a mean UPSIT score of 14.7 (SD 4.7) (normal > 34) despite having been treated with an appropriate diet for a median of 15 years (range 1-25). CONCLUSIONS: Identification of ARD patients can be facilitated by using the UPSIT in combination with the presence of retinitis pigmentosa, even if they have no neurological or bony features. Phytanic acid screening should be performed in any patient manifesting these two signs.

Hearing loss in adult Refsum's disease.

Refsum's disease is characterized by defective peroxisomal alpha oxidation of phytanic acid, with clinical features that include retinitis pigmentosa, polyneuropathy, anosmia and hearing loss. Although hearing loss in Refsum's disease is common, there are few detailed assessments of the site of the abnormality. We examined the audiometric findings in patients with biochemically diagnosed Refsum's disease in order to assess the site of origin of the hearing loss. We found hearing loss, ranging from mild, predominantly high frequency to moderate degree, in seven out of nine patients with biochemically diagnosed adult Refsum's disease. In addition, we found evidence to suggest subtle auditory nerve involvement in six out of the seven patients with hearing loss and in one out of the two patients with a normal pure tone audiogram, on the basis of the ABR test results. We conclude that patients with Refsum's disease who report hearing difficulties should have full audiometric investigations in order to provide appropriate audiological rehabilitation.

[Refsum's disease: evolution 35 years after diagnosis]. / Maladie de Refsum avec 35 ans de recul.

Refsum's disease (Heredopathia atactica polyneuritiformis) is an autosomal recessive disease caused by a defective alpha oxidation of a C20 fatty acid: the phytanic acid. Deficiency of a peroxysomal enzyme called "Phytanoyl-Co-A alpha hydroxylase" leads to an accumulation of phytanic acid. The clinical picture include retinitis pigmentosa, peripheral neuropathy, ataxia and elevated cerebrospinal fluid protein concentration. Firstly described in 1946 by Sigvald Refsum, dietary treatment leads to an improvement of neurological symptoms but does not affect retinal changes. To our knowledge, there is no data in the literature on long term follow-up. A patient with Refsum's disease diagnosed in 1965 presented with facial paralysis. The phytanic acid concentration was low, CSF protein level was normal leading to diagnosis of Bell's palsy. This observation is of particular interest because after 35 years evolution of the disease, the only handicap was visual impairment, with no loss of muscle strength or sensory deficit.

The site of the hearing loss in Refsum's disease.

Refsum's disease is a disorder of lipid metabolism with pigmentary retinopathy, demyelinating neuropathy, ataxia, and hearing loss. Previous histological studies have located the site of hearing impairment in the inner ear, but it has never been confirmed audiologicaly in the literature. In this reported case of Refsum's disease, despite hearing loss and absence of response in ABR, robust otoacoustic emissions were measured. Together with these and other audiological findings, we conclude that our case might be the first reported case of Refsum's disease with auditory neuropathy. The site of the hearing abnormality in Refsum's disease may be 'post-outer hair cells' in some cases as in the current case. Because of their limited benefits and risk of noise-induced damage to outer hair cells, the use of hearing aids before otoacoustic emission measurements should be considered cautiously in Refsum's disease.

Treatable forms of retinitis pigmentosa associated with systemic neurological disorders.

In this chapter; we have described the role of nutritional supplements or selective dietary restriction (or both) on the maintenance and function of the retina and nervous system in some diseases. Oral vitamin A therapy has proven to be effective in the treatment of the common forms of retinitis pigmentosa. Bassen-Kornzweig disease can be treated with vitamin A and vitamin E and, in some cases, with vitamin K. Vitamin E therapy for Friedreich-like ataxia associated with retinitis pigmentosa has been shown to be effective in the short term. Classic Refsum's disease responds to a low phytol-low phytanic acid diet. Undoubtedly, future research will bring more insight into the biochemical pathways responsible for other diseases and, it is hoped, aid in developing treatments for additional retinal degenerations associated with systemic neurological disease.

[Diabetes mellitus in connection with a hereditary disease]. / Diabetes mellitus in samenhang met een erfelijke aandoening.

Diabetes mellitus is usually subdivided into type I (insulin-dependent) and type II (relative insulin shortage and reduced sensitivity to insulin). Diabetes may also be related to pregnancy, malnutrition, pancreatic disease, pharmaceuticals, endocrine diseases and hereditary disorders. The hereditary diseases which may be associated with diabetes mellitus or impaired glucose tolerance can be subdivided into syndromes (such as maternally inherited diabetes and deafness, Down, Turner and Klinefelter syndrome), metabolic diseases (like cystic fibrosis and haemochromatosis) and endocrine diseases (like polyglandular autoimmune insufficiency syndrome and familial phaeochromocytoma). Although diabetes mellitus as part of a hereditary disorder is infrequent, the possibility should be kept in mind with a view to a correct diagnosis. In patients with diabetes mellitus a hereditary disorder may be involved, while patients with a hereditary disorder run a higher risk of developing diabetes mellitus.

[Cardiac involvement in neuromuscular diseases]. / Repercusión cardíaca de las enfermedades neuromusculares.

Many neuromuscular disorders involve the heart, occasionally with overt clinical disease. Muscular dystrophies (dystrophinopathies, limb girdle muscular dystrophy, Emery-Dreifuss muscular dystrophy, Steinert's myotonic dystrophy), congenital myopathies, inflammatory myopathies and metabolic diseases (glycogenosis, periodic paralysis, mitochondrial diseases) may produce dilated or hypertrophic cardiomyopathy and heart rhythm or conduction disturbances. Furthermore the heart is commonly involved in some hereditary and degenerative diseases (Friedreich's ataxia and Kugelberg-Welander syndrome) and acquired (Guillain-Barré syndrome) or inherited (Refsum's disease and Charcot-Marie-Tooth syndrome) polyneuropathies. A cardiologist's high clinical suspicion and a simple but systematic skeletal muscle and peripheral nerve investigation, including muscle enzymes quantification, neurophysiological study and muscle biopsy, are necessary for an accurate diagnosis. In selected patients, more sophisticated biochemical and genetic analysis will be necessary. In most cases, endomyocardial biopsy is not essential for the diagnosis.

[Pauci-symptomatic sensory polyneuropathy in Refsum's disease]. / Polyneuropathie sensitive pauci-symptomatique au cours d'une maladie de Refsum.

Refsum's disease is an autosomal recessive disease caused by defective alpha-oxidation of phytanic acid. The usual clinical presentation is the association of retinitis pigmentosa, ataxia and chronic severe sensorimotor polyneuropathy. A case of mild purely sensory neuropathy in a 40-year-old patient associated to high CSF protein level led to the diagnosis of Refsum's disease. The paucity of sensory symptoms and signs of neuropathy contrasted with severe reduction of motor and sensory nerve conduction velocities and markedly signs of sensory neuropathy observed in the nerve biopsy. Typical ring-scotomas, retinitis pigmentosa, anosmia, deafness, and high plasma phytanic acid level were present in extensive examination. There was no other case in the family.