Manifestaciones oftalmológicas compatibles con el síndrome de Waardenburg / Ophthalmological manifestations compatible with Waardenburg syndrome

RESUMEN El síndrome de Waardenburg es una enfermedad genética, con criterios diagnósticos como la distopia cantorum, las anomalías pigmentarias del iris, el hipertelorismo y la conjunción de las cejas. Se presentan dos casos de una misma familia quienes asistieron a la consulta de Oftalmología con manifestaciones compatibles con el síndrome de Waardenburg. Paciente de 12 años con asociación típica que inclu ye conjunción de las cejas, alteraciones en la pigmentación del iris (iris azul zafiro) y distopia cantorum, a los que se le une el antecedente de hipoacusia. Su madre, paciente de 37 años de edad, quien presenta la asociación típica, inclu ye alteraciones en la pigmentación del cabello (mechón de canas) y del iris (iris azul zafiro), distopia cantorum y antecedente de hipoacusia. El propósito de este estudio fue dar a conocer dos casos de la misma familia con una entidad infrecuente en la especialidad. No obstante, se pueden encontrar manifestaciones oftalmológicas que son compatibles con su diagnóstico, por lo que es elemental dirigir nuestra acción hacia una aten ción en forma interdisciplinaria y una remisión oportuna(AU)

ABSTRACT Waardenburg syndrome is a genetic disorder with diagnostic criteria such as dystopia canthorum, iris pigmentary abnormalities, hypertelorism and synophrys. A case is presented of two members of the same family who attend the ophthalmology service for manifestations compatible with Waardenburg syndrome. The two patients are a 12-year-old girl with a typical association, which includes synophrys, iris pigmentary alterations (brilliant blue iris) and dystopia canthorum, as well as a history of hypoacusis, and her 37-year-old mother, who presents the typical association, which includes alterations in the pigmentation of her hair (a forelock of white hair) and iris (brilliant blue iris), dystopia canthorum and a history of hypoacusis. The purpose of the study is to present two cases from the same family with a condition which is infrequent in the specialty. However, ophthalmological manifestations may be found which are compatible with its diagnosis, which should obviously enough lead to actions aimed at interdisciplinary care and timely referral(AU)

A homozygous MITF mutation leads to familial Waardenburg syndrome type 4.

Waardenburg syndrome (WS) is a genetic disorder characterized by hearing loss and pigmentary abnormalities with variable penetrance. Though heterozygous mutations in MITF are a major cause for Waardenburg syndrome type 2 (WS2), homozygous mutations in this gene and the associated phenotype have been rarely characterized. In this study, we identified a novel p.R223H mutation in MITF in a Chinese Han family with variable WS features. Both parents carried a heterozygous p.R223H mutation. They had normal hearing, and premature greying of the hair is their only pigmentary abnormality. In contrast, their two children both carried a homozygous p.R223H mutation and had classic WS features including profound hearing loss, heterochromia irides and marked pigmentary abnormalities in hair and skin. Interestingly, the two affected children also have persistent chronic constipation since the neonatal period, symptoms suggestive of Waardenburg syndrome type 4 (WS4). Our study revealed a likely association between homozygous mutations in MITF and WS4, which implies a dosage effect for the underlying pathogenesis mechanism.

Poliosis circumscripta: overview and underlying causes.

Although traditionally known as "white forelock," poliosis circumscripta, defined as a localized patch of white hair in a group of hair follicles, can involve any hairy area on the body including the scalp, eyebrows, and eyelashes. Microscopically, poliosis demonstrates either decreased or absent melanin and/or melanocytes in the hair bulbs of the affected hair follicles. Classically, poliosis is known to occur in the setting of several genetic syndromes including piebaldism, Waardenburg, and tuberous sclerosis. In addition, poliosis has been described in association with various acquired conditions. These include inflammatory conditions, benign and malignant neoplastic entities that are mainly melanocytic, medications, and others. In this review, we aim to describe the different conditions where poliosis may be encountered, with the aim of helping the clinician to better evaluate any patient presenting with poliosis.

Cochlear implantation in Waardenburg syndrome: The Indian scenario.

CONCLUSION: Children with Waardenburg syndrome (WS) exhibiting normal inner ear anatomy, like those included in our cohort, derive significant benefit from cochlear implantation and results are comparable to those reported for the general population of implanted children. OBJECTIVES: The patient population of WS accounts for approximately 2% of congenitally deaf children. The purpose of this retrospective case review was to describe the outcomes for those children with WS who have undergone cochlear implantation. METHODS: On retrospective chart review, there were four cases with WS who underwent cochlear implantation. These cases were assessed for age at implantation, clinical and radiological features, operative and perioperative course, and performance outcomes. Auditory perception and speech production ability were evaluated using categories of auditory performance (CAP), meaningful auditory integration scales (MAIS), and speech intelligibility rating (SIR) during the follow-up period. RESULTS: In this group of children with WS, with a minimum follow-up of 12 months, the CAP score ranged from 3 to 5, MAIS from 25 to 30, and SIR was 3. These scores are comparable with those of other cochlear implantees.

Screening program for Waardenburg syndrome in Colombia: clinical definition and phenotypic variability.

A screening program to detect Waardenburg syndrome (WS) conducted between 2002 and 2005, among 1,763 deaf individuals throughout Columbia identified 95 affected individuals belonging to 95 families, giving a frequency of 5.38% of WS among the institutionalized deaf population. We confirmed the clinical diagnosis of WS in the 95 propositi and, through the family evaluation, we also identified 45 non-institutionalized affected relatives. Audiologic, ophthalmologic, and genetic studies were performed to confirm the diagnosis. Following the classification of the WS consortium, based on the Waardenburg Index (WI), to define the type of WS. We classified 62.1% of the propositi as WS2 and 37.9% as WS1. We present here the results of the study of clinical manifestations, analyzing the presence, severity, and symmetry of clinical findings among this affected population. Overall, among the 95 propositi, in addition to sensorineural deafness in all, the most frequent features were broad nasal root (58.9%), a first degree relative affected (37.9%), heterochromia irides (36.8%), skin hypopigmentation (31.6%), white forelock (28.0%), intense blue iris (27.4%), synophrys (12.6%), premature graying (10.5%), ptosis of the eyelids (9.5%), and hypoplasia alae nasi (1.1%). The majority of individuals had normal psychomotor development (87%), while the remaining 13% had developmental delay. Among the latter, 9.4% corresponded to WS2 and 3.6% to WS1. Our data confirm an interesting inter- and intrafamilial variability in the phenotypic manifestations as well as extremely variable expression.

Waardenburg syndrome in the Turkish deaf population.

Waardenburg Syndrome (WS) is an autosomal, dominantly inherited disorder that accounts for more than 2% cases of congenital deafness. The aim of this study is to determine the WS incidence among deaf pupils. Dysmorphological examination was performed on 720 children who were attending 7 special schools in Turkey and who had hearing disabilities. All subjects in the study were examined for WS diagnostic criteria. We detected 49 patients (6.8%) with WS among the 720 children examined. Six patients had WS type 1 (12.2%) and 43 had type 2 (87.8%). We observed 2 to 5 major diagnostic criteria for WS. Out of all the subjects in the study, only two patients have deaf first degree relatives. All subjects had been previously examined by physicians for deafness but none of them had been then diagnosed to have Waardenburg Syndrome. Instead, they were all misdiagnosed as to have nonsyndromic deafness. Awareness of WS diagnostic criteria by the physicans will provide accurate diagnosis for many deaf pupils and their first degree relatives who are able-to-hear WS patients and whose children are at risk for deafness.

[Waardenburg syndrome. A heterogenic disorder with variable penetrance]. / Waardenburg-Syndrom. Eine heterogene Erkrankung mit variabler Penetranz.

BACKGROUND: Waardenburg syndrome (WS) is an autosomal dominant disorder characterised by pigmentary anomalies of the skin, hairs, eyes and various defects of other neural crest derived tissues. It accounts for over 2% of congenital hearing impairment. At least four types are recognized on the basis of clinical and genetic criteria. PATIENTS AND METHODS: Based on a screening of congenitally hearing impaired children, 12 families with WS type II were detected. Of special interest was the phenotype of these families, in particular the reduced penetrance of hearing impairment within the families. RESULTS AND CONCLUSION: In all cases a high variability of the disease phenotype was detected and the penetrance of the clinical traits varied accordingly. Therefore, it is not possible to predict the clinical phenotype even in a single family. Based on these studies, we plan to identify the pathogenetic cause of the disease in order to perform a detailed genotype/phenotype analysis.

Intestinal aganglionosis associated with the Waardenburg syndrome: report of two cases and review of the literature.

The authors report two cases of the rare concurrence of intestinal aganglionosis and Waardenburg syndrome in Japanese infants. The patients were a 1-month-old girl and a 3-month-old boy at diagnosis, and both of them had either short segment or ultra-short segment aganglionosis. A review of 48 cases in the literature showed that the extent of the aganglionic segment is quite variable, from nearly total to ultra-short. The clinical features of aganglionosis in Waardenburg syndrome would appear to bear similarity in sex ratio and the extent of aganglionosis with those of Hirschsprung's disease associated with Ondine's curse, another type of neurocristopathy.

Temporal bone abnormalities associated with hearing loss in Waardenburg syndrome.

OBJECTIVES/HYPOTHESIS: The objectives were to correlate audiometric thresholds with radiological findings and to determine the prevalence of inner ear radiological abnormalities in patients with hearing loss and Waardenburg syndrome. STUDY DESIGN: The study was a retrospective review of patients with Waardenburg syndrome identified in a pediatric hearing-impaired population and human genetics clinic. METHODS: Nine children with Waardenburg syndrome were identified. Eighty-nine children without sensorineural hearing loss served as control subjects. Clinical data, audiometric thresholds, and radiographic temporal bone measurements in these children were analyzed. RESULTS: Seven children were identified with hearing loss and Waardenburg syndrome. Four children had Waardenburg syndrome type 1, and three children had Waardenburg syndrome type 2. The overall prevalence of hearing loss in the total study population with Waardenburg syndrome was 78%. The mean pure-tone average was 99 dB. All of the children had sensorineural hearing loss. The hearing outcome was stable in 86% of the children. Twelve temporal bones were available for radiological analysis by computed tomography. Enlargement of the vestibular aqueduct was found in 50% of the CT scans. There was a significant difference in measurements of vestibular aqueduct width at the midpoint between the patients with Waardenburg syndrome and the control group (P <.05). There were also significant differences in the measurements of the vestibule (P =.0484), internal auditory canal (P =.0092), and modiolus (P =.0045) between the children with Waardenburg syndrome and the control group. CONCLUSION: A profound sensorineural hearing loss was characteristic of the study population with Waardenburg syndrome. Overall, 100% of patients with hearing loss and Waardenburg syndrome had temporal bone anomalies on at least one measurement of their inner ear, and 50% had an enlargement of the vestibular aqueduct at the midpoint. As shown by computed tomography, enlargement of the vestibular aqueduct and the upper vestibule, narrowing of the internal auditory canal porus, and hypoplasia of the modiolus are features of Waardenburg syndrome.

Worldwide distribution of Waardenburg syndrome.

To clarify the multiracial occurrence of Waardenburg syndrome, we present a case series and literature review. A computerized review of the English-language literature was conducted to assess the distribution of reported occurrences of Waardenburg syndrome in populations around the world. We detail the clinical features of 2 family cohorts: one of Western European origin and the other from South Asia. A computerized literature review found sporadic cases of the syndrome in many ethnic groups, including Japanese, Taiwanese, and Middle Eastern families. The highest reported incidence is among Kenyan Africans. Waardenburg syndrome accounts for between 2% and 5% of cases of congenital deafness. It was first described in Northern European cohorts and is widely identified in fair-skinned populations. We hope to raise awareness of the worldwide distribution of this important cause of hearing loss.

Waardenburg syndrome.

Auditory-pigmentary syndromes are caused by physical absence of melanocytes from the skin, hair, eyes, or the stria vascularis of the cochlea. Dominantly inherited examples with patchy depigmentation are usually labelled Waardenburg syndrome (WS). Type I WS, characterised by dystopia canthorum, is caused by loss of function mutations in the PAX3 gene. Type III WS (Klein-Waardenburg syndrome, with abnormalities of the arms) is an extreme presentation of type I; some but not all patients are homozygotes. Type IV WS (Shah-Waardenburg syndrome with Hirschsprung disease) can be caused by mutations in the genes for endothelin-3 or one of its receptors, EDNRB. Type II WS is a heterogeneous group, about 15% of whom are heterozygous for mutations in the MITF (microphthalmia associated transcription factor) gene. All these forms show marked variability even within families, and at present it is not possible to predict the severity, even when a mutation is detected. Characterising the genes is helping to unravel important developmental pathways in the neural crest and its derivatives.

The Waardenburg syndrome in deaf children in southern Africa.

Eighty-nine children with the Waardenburg syndrome were identified during diagnostic surveys of 3006 deaf children attending 19 special schools in southern Africa. Since a hearing deficit is present in only a minority of persons with the Waardenburg syndrome, it can be estimated that there are several thousand individuals with the faulty gene among the local population. The syndrome was encountered in deaf children of White, Black and mixed ancestry but not in Indian scholars. There were marked discrepancies in prevalence in different tribal groups. In several sets of deaf siblings, one individual had the classic syndromic stigmata while the other had apparently undifferentiated perceptive deafness. On this basis it is possible that phenotypic expression of the Waardenburg gene in some persons may be limited to a hearing deficit. Our observations indicate that the sole manifestation of the faulty gene can be irides of a uniform, striking and unusual blue colour, with or without congenital deafness.

Waardenburg's syndrome in Kenyan Africans.

Waardenburg's syndrome is characterized by deafness and pigment disorders of the eyes, hair and skin. Two types are distinguished; e.g. type I with dystopia canthorum and type II without dystopia canthorum. In Kenya 12 out of 724 pupils of schoools for the deaf were found to suffer from the syndrome. Ten of these belonged to eight families; 20 other members of these families had signs of the syndrome. Of these 30 patients 18 had type I, 12 type II. The expression of most characteristics in these Kenyan patients was almost the same as in Caucasians. The mode of inheritance was autosomal dominant, as in Caucasians. The interocular distances were measured in 168 healthy children and adults of the Luo tribe. In most age groups slightly larger values were found than in the Caucasian race. For the diagnosis of dystopia canthorum this should be taken into account.