Prenatal testing for Huntington's disease in the Netherlands from 1998 to 2008.

This study aims to give an overview of the number of prenatal tests for Huntington's disease (HD), test results, and pregnancy outcomes in the Netherlands between 1998 and 2008 and to compare them with available data from the period 1987 to 1997. A total of 126 couples underwent prenatal diagnosis (PND) on 216 foetuses: 185 (86%) direct tests and 31 (14%) exclusion tests. In 9% of direct tests the risk for the foetus was 25%. Four at-risk parents (4%) carried intermediate alleles. Ninety-one foetuses had CAG expansions ≥36% or 50% risk haplotypes: 75 (82%) were terminated for HD, 12 (13%) were carried to term; four pregnancies were miscarried, terminated for other reasons or lost to follow-up. Unaffected pregnancies (122 foetuses) resulted in the birth of 112 children. The estimated uptake of PND was 22% of CAG expansion carriers (≥36 repeats) at reproductive age. PND was used by two new subgroups: carriers of intermediate alleles and 50% at-risk persons opting for a direct prenatal test of the foetus. A significant number of HD expansion or 50% risk pregnancies were continued. Speculations were made on causative factors contributing to these continuations. Further research on these couples' motives is needed.

WRN mutations in Werner syndrome patients: genomic rearrangements, unusual intronic mutations and ethnic-specific alterations.

Werner syndrome (WS) is an autosomal recessive segmental progeroid syndrome caused by null mutations at the WRN locus, which codes for a member of the RecQ family of DNA helicases. Since 1988, the International Registry of Werner syndrome had enrolled 130 molecularly confirmed WS cases from among 110 worldwide pedigrees. We now report 18 new mutations, including two genomic rearrangements, a deep intronic mutation resulting in a novel exon, a splice consensus mutation leading to utilization of the nearby splice site, and two rare missense mutations. We also review evidence for founder mutations among various ethnic/geographic groups. Founder WRN mutations had been previously reported in Japan and Northern Sardinia. Our Registry now suggests characteristic mutations originated in Morocco, Turkey, The Netherlands and elsewhere.

Spinocerebellar ataxia type 6 (SCA6): neurodegeneration goes beyond the known brain predilection sites.

AIMS: Spinocerebellar ataxia type 6 (SCA6) is a late onset autosomal dominantly inherited ataxic disorder, which belongs to the group of CAG repeat, or polyglutamine, diseases. Although, it has long been regarded as a 'pure' cerebellar disease, recent clinical studies have demonstrated disease signs challenging the view that neurodegeneration in SCA6 is confined to the well-known lesions in the cerebellum and inferior olive. METHODS: We performed a systematic pathoanatomical study throughout the brains of three clinically diagnosed and genetically confirmed SCA6 patients. RESULTS: This study confirmed that brain damage in SCA6 goes beyond the known brain predilection sites. In all of the SCA6 patients studied loss of cerebellar Purkinje cells and absence of morphologically intact layer V giant Betz pyramidal cells in the primary motor cortex, as well as widespread degeneration of brainstem nuclei was present. Additional damage to the deep cerebellar nuclei was observed in two of three SCA6 patients. CONCLUSIONS: In view of the known functional role of affected central nervous grey components it is likely that their degeneration at least in part is responsible for the occurrence of a variety of SCA6 disease symptoms.

Spinocerebellar ataxia type 7 (SCA7): first report of a systematic neuropathological study of the brain of a patient with a very short expanded CAG-repeat.

Spinocerebellar ataxia type 7 (SCA7) represents a very rare and severe autosomal dominantly inherited cerebellar ataxia (ADCA). It belongs to the group of CAG-repeat or polyglutamine diseases with its underlying molecular genetical defect on chromosome 3p12-p21.1. Here, we performed a systematic study of the neuropathology on unconventional thick serial sections of the first available brain tissue of a genetically confirmed late-onset SCA7 patient with a very short CAG-repeat expansion. Along with myelin pallor of a variety of central nervous fiber tracts, we observed i) neurodegeneration in select areas of the cerebral cortex, and ii) widespread nerve cell loss in the cerebellum, thalamus, nuclei of the basal ganglia, and brainstem. In addition, upon immunocytochemical analysis using the anti-polyglutamine antibody 1C2, immunopositive neuronal intranuclear inclusions bodies (NI) were observed in all cerebellar regions, in all parts of the cerebral cortex, and in telencephalic and brainstem nuclei, irrespective of whether they underwent neurodegeneration. These novel findings provide explanations for a variety of clinical symptoms and paraclinical findings of both our and other SCA7 patients. Finally, our immunocytochemical analysis confirms previous studies which described the presence of NI in obviously degenerated brain and retinal regions as well as in apparently well-preserved brain regions and retina of SCA7 patients.

Spinocerebellar ataxias in the Netherlands: prevalence and age at onset variance analysis.

BACKGROUND: International prevalence estimates of autosomal dominant cerebellar ataxias (ADCA) vary from 0.3 to 2.0 per 100,000. The prevalence of ADCA in the Netherlands is unknown. Fifteen genetic loci have been identified (SCA-1-8, SCA-10-14, SCA-16, and SCA-17) and nine of the corresponding genes have been cloned. In SCA-1, SCA2, SCA3, SCA6, SCA7, SCA-12 and SCA-17 the mutation has been shown to be an expanded CAG repeat. Previously, the length of the CAG repeat was found to account for 50 to 80% of variance in age at onset. Because of heterogeneity in encoded proteins, different pathophysiologic mechanisms leading to neurodegeneration could be involved. The relationship between CAG repeat length and age at onset would then differ accordingly. METHOD: Based on the results of SCA mutation analysis in the three DNA diagnostic laboratories that serve the entire Dutch population, the authors surveyed the number of families and affected individuals per SCA gene, as well as individual repeat length and age at onset. Regression analysis was applied to study the relationship between CAG repeat length and age at onset per SCA gene. The slopes of the different regression curves were compared. RESULTS: On November 1, 2000, mutations were found in 145 ADCA families and 391 affected individuals were identified. The authors extrapolated a minimal prevalence of 3.0 per 100,000 (range 2.8 to 3.8/100,000). SCA3 was the most frequent mutation. CAG repeat length contributed to 52 to 76% of age at onset variance. Regression curve slopes for SCA-1, SCA2, SCA3, and SCA7 did not differ significantly. CONCLUSIONS: The estimated minimal prevalence of ADCA in the Netherlands is 3.0 per 100,000 inhabitants. Except for SCA6, the relationship between age at onset and CAG repeat expansion does not differ significantly between SCA-1, SCA2, SCA3, and SCA7 patient groups in our population, indicating that these SCA subtypes share similar mechanisms of polyglutamine-induced neurotoxicity, despite heterogeneity in gene products.

Cardiac involvement in carriers of Duchenne and Becker muscular dystrophy.

A cross-sectional study in a cohort of DNA proven carriers of Duchenne (DMD) and Becker (BMD) muscular dystrophy was undertaken with the following objectives: (1) to estimate the frequency of electrocardiographic (ECG) and echocardiographic abnormalities; (2) to establish the proportion of carriers with dilated cardiomyopathy and (3) to assess possible associations between dilated cardiomyopathy and genotype. One hundred and twenty nine DMD and BMD carriers, aged 18-60 years, were traced through the files of the central register kept at the department of Human Genetics in Leiden. Investigations included full medical history, physical examination, ECG and two-dimensional and M-mode echocardiographic examination. Forty-seven percent had ECG changes. Thirty-six percent (DMD 41%, BMD 27%) had at least one abnormality as is usually found in the male patients. Echocardiographic examination was abnormal in 36% (DMD 38%, BMD 34%). Dilated cardiomyopathy was found in seven DMD carriers (8%), and in none of BMD carriers. In addition, 18% had left ventricle dilatation (DMD 19%, BMD 16%). Only 38% had a completely normal investigation of the heart. We found no association between genotype and cardiac manifestations. Our study underlines that cardiac involvement is part of the dystrophinopathies. Carriers should be told about the increased risk of this complication when asking genetic advice. It also implicates that a complete cardiological evaluation should be performed at least once in all carriers. If left ventricle dilatation or dilated cardiomyopathy is present a yearly follow up is needed, in order to start timely therapy.

Craniofacial dysostosis, hypertrichosis, genital hypoplasia, ocular, dental, and digital defects: confirmation of the Gorlin-Chaudhry-Moss syndrome.

We report clinical, orofacial and radiological manifestations in a 4-year-old girl and a 33-year-old female with the Gorlin-Chaudhry-Moss (GCM) syndrome. Typical findings in the GCM syndrome are short stature, stocky body build, midface hypoplasia, small eyes, downslanting palpebral fissures, conductive hearing loss, highly arched and narrow palate, malocclusion, abnormally shaped teeth, oligodontia, microdontia, low scalp hairline, hypertrichosis of scalp, face, trunk and limbs and genital hypoplasia. Radiological features include premature synostosis of the coronal suture, brachycephaly, and maxillary under-development. Hypoplasia of the distal phalanges of fingers and toes (also present in the 2 original cases) represents a further manifestation of the GCM syndrome.

The Pena-Shokeir syndrome: report of nine Dutch cases.

We report on nine individuals with the Pena-Shokeir syndrome. Clinical findings are compared with data on patients from the literature. Emphasis is made on genetic background, neuropathological findings, and (in two cases) on prenatal data. Possible pathogenetic mechanisms are discussed.

Clinical and genetic analysis of a four-generation family with a distinct autosomal dominant cerebellar ataxia.

The autosomal dominant cerebellar ataxias (ADCAs) are a heterogeneous group of neurodegenerative disorders characterised by progressive cerebellar dysfunction in combination with a variety of other associative features. Since 1993 ADCAs have been increasingly characterised in terms of their genetic mutation and are referred to as spinocerebellar ataxias (SCAs). Some families with ADCA cannot be assigned to any of the known genotypes, which implies further genetic heterogeneity. We investigated the clinical symptoms of 12 patients of a four-generation family with ADCA and carried out mutation and genetic linkage studies. The family showed a relatively mild cerebellar ataxic syndrome with cognitive impairment, poor performance on the Wisconsin Card Sorting Test, myoclonus, and a postural irregular tremor of slow frequency. Age at disease onset and severity of cerebellar signs and symptoms suggest anticipation. The genetic loci implicated in ADCA were excluded by mutation analyses (SCA 1, 2, 3, 6, 7, 8, 12) and genetic linkage (SCA 4, 5, 6, 10, 11). We conclude that this family represents a clinically and genetically distinct form of SCA.

Sutural cataract, retinitis pigmentosa, microcephaly and psychomotor retardation. A new autosomal recessive disorder?

We report four children (three sibs and one sporadic case) with congenital sutural cataract (opacity of the sutures of the crystalline lens), retinitis pigmentosa (leading to diminished visual acuity), microcephaly, and moderate to severe psychomotor retardation. The three sibs (two F and one M) were born to healthy, consanguineous Moroccan parents; the sporadic case is an 11-year-old Dutch girl who presented at the age of nine months with a small head circumference (third percentile) and sutural cataract. Psychomotor development was retarded in all cases, retinitis pigmentosa became evident during middle or late childhood. Congenital cataract has been described in association with a large number of various congenital abnormalities, such as renal, nervous system, skeletal, dermal and ocular (including retinal) defects. A computer-assisted literature search has not revealed similar cases to those presented here. The cases described here appear to have a previously undescribed combination of ophthalmological and cerebral abnormalities. The inheritance of the condition appears to be autosomal recessive as a brother and two sisters (offspring of normal consanguineous parents) are affected. The differential diagnosis is discussed.

A Dutch family with benign hereditary chorea of early onset: differentiation from Huntington's disease.

A large Dutch family of 88 members, running through five generations, is described with benign hereditary chorea of early onset. The clinical presentation was heterogeneous. The chorea manifested in late infancy or childhood, interfered with writing, was non-disabling, stable or even improved in adulthood in most cases, but was slowly progressive with gait impairment in some. There was mild dysarthria and normal intelligence. EEG brain CT-scanning and MRI were normal. Huntington's disease was excluded by analysis of the I T 15 gene, which showed a normal number of the CAG trinucleotide repeats in two patients. It is concluded that benign hereditary chorea of early onset is an entity different from Huntington's disease and that in cases of early onset chorea the diagnostic accuracy is markedly improved by DNA testing.

Interstitial deletion 11q. Case report and review of the literature.

A mildly retarded male with a unique interstitial deletion 11 (pter-->q22.3::q23.2-->qter) is described. To the best of our knowledge this patient is the first case with this specific type of deletion. The clinical features and cytogenetic findings of this patient are compared with those of previously reported cases with interstitial deletions 11q and patients with terminal deletions involving band 11q24.1 (leading to the so-called Jacobsen syndrome).

DOOR syndrome: additional case and literature review.

We report on a patient with sensorineural deafness, onycho- and osteodystrophy and mental retardation (DOOR syndrome) and review the literature. It appears that abnormal dermatoglyphics are a frequent feature of the DOOR syndrome, as all patients with DOOR syndrome in whom dermatoglyphic investigations were done, had multiple arches on their fingertips.

Greig cephalopolysyndactyly syndrome in a large family: a comparison of the clinical signs with those described in the literature.

We report on a four generation family with Greig cephalopolysyndactyly syndrome. The clinical variability of the malformations of hands and feet is described. A review of the literature is given, with emphasis on the frequency of clinical signs of the Greig cephalopolysyndactyly syndrome. Polydactyly of the hands and feet are possibly an underestimated feature in Greig syndrome. We suggest that radiographs of the hands and feet should be performed in every patient, especially those with broad thumbs. The resemblance of preaxial polydactyly type 4 and crossed polydactyly with Greig syndrome is discussed. These disorders may be allelic.

[A newborn infant with the xxxxy-syndrome]. / Een pasgeborene met het XXXXY-syndroom.

In a three weeks old infant with dysmorphic features a 49, XXXXY karyotype was demonstrated from chromosome preparations of lymphocytes. In the literature only a few newborn infants have been described with this syndrome. The most frequent symptoms of the syndrome in older patients are mental retardation, dysmorphic signs, hypogonadism and skeletal malformations. In our patient we found a low birth weight, a peculiar facies, in addition to a patent ductus arteriosus, a scoliosis and normal external genitals. The most typical skeletal malformations may develop at a more advanced age.

Cardiac abnormalities in a follow-up study on carriers of Duchenne and Becker muscular dystrophy.

OBJECTIVES: Cardiac involvement has been reported in carriers of dystrophin mutations giving rise to Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD). The progress of these abnormalities during long-term follow-up is unknown. We describe the long-term follow-up of dilated cardiomyopathy (DCM) in DMD/BMD carriers. METHODS: A long-term follow-up study was performed among Dutch DMD/BMD carriers first analyzed in 1995. A cardiac history was taken, and all carriers were assigned a functional score to assess skeletal muscle involvement. Electrocardiography and M-mode and 2-D echocardiography were performed. DCM was defined as an enlarged left ventricle with a global left ventricle dysfunction or fractional shortening less than 28%. Slow vital capacity of the lung was measured by a hand-held spirometer. RESULTS: Ninety-nine carriers were monitored with a median follow-up of 9 years (range 7.0-10.6 years). Eleven carriers with DCM (10 DMD, 1 BMD) were identified. Nine of them developed DCM in the follow-up period. One of the patients with DCM reported in the 1995 study died of cardiac failure at age 57 years. DCM was more frequently found in carriers who were functionally symptomatic. CONCLUSION: Cardiac abnormalities in DMD/BMD carriers are progressive, as in patients with DMD/BMD.

Gly118Asp is a SCA14 founder mutation in the Dutch ataxia population.

Missense mutations in the PRKCG gene have recently been identified in spinocerebellar ataxia 14 (SCA14) patients; these include the Gly118Asp mutation that we found in a large Dutch autosomal dominant cerebellar ataxia (ADCA) family. We subsequently screened the current Dutch ataxia cohort (approximately 900 individuals) for SCA14 mutations in the Cys2 region of the PRKCG gene. We identified the Gly118Asp mutation in another eight individuals from five small families. Haplotype analysis identified a shared chromosomal region surrounding the SCA14 gene, and genealogical research was able to link all these ADCA patients to a single common ancestor. We therefore confirmed that the Gly118Asp mutation is a SCA14 founder mutation in the Dutch ADCA population.

Autosomal dominant congenital Horner's syndrome in a Dutch family.

A Dutch family is reported with congenital Horner's syndrome in five cases spanning five generations, with symptoms of varying degree but mainly ptosis and meiosis. Heterochromia iridium, anhidrosis, and enophthalmos were not present. The site of the lesion may be in the region between Gasser's ganglion and the short vertical segment of the internal carotid artery near the siphon. There are only four previous reports showing autosomal dominant inheritance of congenital Horner's syndrome.

Similarities and differences in the phenotype, genotype and pathogenesis of different spinocerebellar ataxias.

Historically, the differential diagnosis of the autosomal ataxias (ADCAs) has been difficult. In 1983 Harding proposed a useful clinical classification. Since 1983 ADCAs have been increasingly characterized in terms of their genetic locus and are referred to as spinocerebeller ataxia (SCA). The overlap between the SCA phenotypes and the high variability within SCA subgroups means that, for individual patients, the underlying mutation cannot be predicted reliable purely on the basis of clinical symptoms and so diagnosis should be made on the genotype. However, for executing DNA analyses in order of clinical likelihood, neurologists may try to deduce the underlying mutation by using a clinical algorithm. In this article we not only describe such an algorithm but also plot the pathway from clinical presentation, genetic classification and mutation, abnormal protein to common neuropathology in these disorders.