Hunter syndrome with late age of presentation: clinical description of a case and review of the literature.

Hunter syndrome is an X linked recessive mucopolysaccharidosis (type II) caused by the deficiency of iduronate 2-sulfatase. This in turn leads to the accumulation of glycosaminoglycans, dermatan and heparan sulfate. The intracellular and extracellular accumulation of these substances lead to multisystemic organ abnormality. It is a rare syndrome with a very low prevalence of 1.3:100,000 male live births. Usual presentation is in early childhood although milder variants have been documented to present at a later age. We present a rare case of Hunter syndrome in a 24-year-old male patient who presented with joint contractures and recent onset hoarseness of voice. X-rays were suggestive of dysostosis multiplex. Clinical diagnosis of Hunter syndrome was confirmed by enzyme assay and further by mutational analysis.

Genetic and environmental effects on vocal symptoms and their intercorrelations.

PURPOSE: Recently, Simberg et al. (2009) found genetic effects on a composite variable consisting of 6 vocal symptom items measuring dysphonia. The purpose of the present study was to determine genetic and environmental effects on the individual vocal symptoms in a population-based sample of Finnish twins. METHOD: The sample comprised 1,728 twins (125 monozygotic and 108 dizygotic twin pairs) born between 1961 and 1989, who completed a questionnaire concerning 6 vocal symptoms. Values for additive genetic, dominant genetic, shared environmental, and nonshared environmental components were computed separately for all symptoms. Multivariate analyses to determine genetic and environmental associations between the vocal symptoms were also performed. RESULTS: Variance was explained by significant additive genetic effects (27%) in only one of the vocal symptoms, namely, voice gets low or hoarse, whereas the variance of one of the vocal symptoms, voice gets strained or tires, could be explained by nonshared environmental influence alone. Multivariate analyses showed that the correlations for most of the symptom combinations were significant. CONCLUSIONS: Both genetic and environmental components influence vocal symptoms. Genetic and environmental influences seem to be differently balanced in different vocal symptoms. Genetic effects are moderate, whereas environmental effects seem to be the most important factor contributing to the presence of vocal symptoms.

Sulcus vocalis: evidence for autosomal dominant inheritance.

We found evidence of autosomal dominant hereditary transmission of sulcus vocalis. Four dysphonic patients from three generations of the same family were submitted to videolaryngoscopic examination (three patients) and to direct laryngoscopy (one patient) to diagnose the hoarseness. Sulcus vocalis was diagnosed in all four patients. The finding of four affected individuals in three generations, with vertical transmission affecting man and women, is more consistent with autosomal dominant inheritance pattern; it is an etiological model that we propose for the sulcus vocalis in this pedigree.

A complex phenotype of peripheral neuropathy, myopathy, hoarseness, and hearing loss is linked to an autosomal dominant mutation in MYH14.

Both peripheral neuropathy and distal myopathy are well-established inherited neuromuscular disorders characterized by progressive weakness and atrophy of the distal limb muscles. A complex phenotype of peripheral neuropathy, myopathy, hoarseness, and hearing loss was diagnosed in a large autosomal dominant Korean family. A high density single nucleotide polymorphism (SNP)-based linkage study mapped the underlying gene to a region on chromosome 19q13.3. The maximum multipoint LOD score was 3.794. Sequencing of 34 positional candidate genes in the segregating haplotype revealed a novel c.2822G>T (p.Arg941Leu) mutation in the gene MYH14, which encodes the nonmuscle myosin heavy chain 14. Clinically we observed a sequential pattern of the onset of muscle weakness starting from the anterior to the posterior leg muscle compartments followed by involvement of intrinsic hand and proximal muscles. The hearing loss and hoarseness followed the onset of distal muscle weakness. Histopathologic and electrodiagnostic studies revealed both chronic neuropathic and myopathic features in the affected patients. Although mutations in MYH14 have been shown to cause nonsyndromic autosomal dominant hearing loss (DFNA4), the peripheral neuropathy, myopathy, and hoarseness have not been associated with MYH14. Therefore, we suggest that the identified mutation in MYH14 significantly expands the phenotypic spectrum of this gene.

Autosomal dominant hereditary sensory neuropathy with chronic cough and gastro-oesophageal reflux: clinical features in two families linked to chromosome 3p22-p24.

Autosomal dominant hereditary sensory neuropathy (HSN I) is a clinically and genetically heterogeneous group of disorders, and in some families it is due to mutations in the serine palmitoyltransferase (SPTLC1) gene. We have characterized two families with HSN I associated with cough and gastro-oesophageal reflux (GOR). From a large Australian family, 27 individuals and from a smaller family, 11 individuals provided clinical information and blood for genetic analysis. Affected individuals had an adult onset of paroxysmal cough, GOR and distal sensory loss. Cough could be triggered by noxious odours or by pressure in the external auditory canal (Arnold's ear-cough reflex). Other features included throat clearing, hoarse voice, cough syncope and sensorineural hearing loss. Neurophysiological and pathological studies demonstrated a sensory axonal neuropathy. Gastric emptying studies were normal, and autonomic function and sweat tests were either normal or showed distal hypohidrosis. Cough was likely to be due to a combination of denervation hypersensitivity of the upper airways and oesophagus, and prominent GOR. Most affected individuals were shown on 24 h ambulatory oesophageal pH monitoring to have multiple episodes of GOR, closely temporally associated with coughing. Hoarse voice was probably attributable to acid-induced laryngeal damage, and there was no evidence of vocal cord palsy. No other cause for cough was found on most respiratory or otorhinological studies. Linkage to chromosome 3p22-p24 has been found in both families, with no evidence of linkage to loci for known HSN I, autosomal dominant hereditary motor and sensory neuropathy, hereditary GOR or triple A syndrome. These families represent a genetically novel variant of HSN I, with a distinctive cough owing to involvement of the upper aerodigestive tract.

Clinical and molecular characterization of lipoid proteinosis in Namaqualand, South Africa.

BACKGROUND: Lipoid proteinosis (LiP) is a rare autosomal recessive disorder characterized by a hoarse voice, warty skin infiltration and scarring. Mutations within the extracellular matrix protein 1 (ECM1) gene cause LiP. Since the early 1970s it has been recognized that South Africa has one of the largest groups of LiP patients worldwide, suggesting a probable founder effect. As LiP patients present with considerable clinical variability, this group of patients offers a unique opportunity for genotype-phenotype correlation. OBJECTIVES: To assess the clinical features and the molecular basis of LiP in patients from the Namaqualand area of the Northern Cape province of South Africa and to examine molecular evidence for a founder effect. SUBJECTS AND METHODS: The LiP patient cohort consisted of 29 Coloured patients from Namaqualand and a further seven Caucasoid patients from other areas of South Africa. The control group included 100 healthy geographically and ethnically matched individuals from Namaqualand. Samples were collected after informed consent and with ethics committee approval from the University of the Witwatersrand. LiP patients were examined clinically and a structured recording sheet was completed. A brief neurological evaluation was also performed. The LiP founder effect was investigated at the molecular level by ECM1 mutation detection and haplotype analysis. RESULTS: The most consistent clinical signs for a diagnosis of LiP in this group were a hoarse voice and thickened sublingual frenulum leading to restricted tongue movement. Homozygosity for a nonsense mutation in exon 7 of the ECM1 gene, Q276X, was identified in all patients (Coloured and Caucasoid). Despite this genetic homogeneity, considerable clinical variability in skin presentation and psychiatric involvement was observed. Haplotype analysis using markers from a 9.98-Mb region around the ECM1 locus confirmed the founder effect with a founder core haplotype, 19-Q276X-12 (ND1-ECM1-D1S2343), in all but four LiP-associated alleles (n = 58). A LiP carrier rate of 1 in 9 was observed among the 100 Namaqualand controls, predicting a LiP incidence of 1 in 324 in this community. CONCLUSIONS: Although several consistent clinical features in LiP patients homozygous for the Q276X mutation in the ECM1 gene were observed, there remains considerable clinical variability. This suggests the action of genetic and environmental modifiers of disease severity. Strong molecular evidence supports a single founder effect for the high prevalence of LiP in South Africans, both Coloured and Caucasoid.

[Farber disease: a cause of hoarseness of the voice in children]. / Maladie de Farber: une cause de raucité de voix chez les enfants.

Farber's disease (disseminated lipogranulomatosis) is an autosomal recessive disease characterized by deposition of glycolipid ceramide in different tissues due to deficiency of lysosomal acid ceramidase. The disease starts to manifest at the age of four months by a hoarse cry or swollen tender joints followed by subcutaneous nodules. This disease is fatal in the first years of life and no treatment is known until now. This study presents four cases of Farber's disease who all presented by hoarseness of voice, polyarthritis and subcutaneous nodules. After clinical examination, the diagnosis was confirmed by fiberoptic flexible nasopharyngolaryngoscopy which showed the presence of vocal folds thickening in all patients and affection of the cricoarytenoid joint in one patient and biopsy from the subcutaneous nodules which showed infiltration of the deep dermis and subcutaneous tissues by fibroblasts and large foamy histiocytes.

Discrete subaortic stenosis as part of a short stature syndrome.

Observations in a family point to the existence of autosomal dominant inheritance for discrete subaortic stenosis (DSS), which made up part of a multisystem disorder. Both parents, offspring of two full siblings, had short stature, obstructive lung disease (OLD), hoarseness and upturned nose. The father alone had aortic stenosis and inguinal hernia. The six offspring, aged from 13 to 28 years, were followed up for up to 8 years. While one of them was virtually normal, and one had only minor abnormalities, four siblings displayed clinical signs of progressive aortic stenosis. Of the two eldest siblings who eventually died, necropsy in one showed a discrete subaortic stenosis, which was hemodynamically proven in one and surgically corrected in another sibling. Upturned nose was present in each examined member of the family, short stature and hoarseness in five of the siblings, DSS in four, OLD, inguinal hernia and congested episcleral veins in three, kyphoscoliosis in two, while epicanthus, strabismus, microphthalmos and widely spaced teeth were noted in the deceased female. The prevalence of some of these traits in roughly three-quarters of the sibship was consistent with an underlying single gene abnormality in affected heterozygous parents. We proposed that this constitutes a new syndrome.

The Dubowitz syndrome: the psychological status of ten cases at follow-up.

We report the psychological status of ten people with the Dubowitz syndrome, an autosomal recessive condition characterized by intrauterine and postnatal growth retardation, microcephaly, and high-pitched hoarse voice. Results indicate that the level of intellectual functioning among children with Dubowitz syndrome varies from severe retardation to average intelligence. Our patients have delays in the development of memory, reasoning, expressive vocabulary, fine motor development, and receptive vocabulary, in order of ascending frequency. Data regarding growth status, level of adaptive functioning, and presence of behavioral deficits are also presented.

Pachyonychia congenita with involvement of the larynx.

Pachyonychia congenita is a genetic syndrome of epithelial dysplasia that is inherited as an autosomal dominant trait. Its unique involvement within the larynx of a 3-year-old boy prompted this brief report of its clinical behavior and management.