Low grade mosaic for a complex supernumerary ring chromosome 18 in an adult patient with multiple congenital anomalies

Background. Several cases have been reported of patients with a ring chromosome 18 replacing one of the normal chromosomes 18. Less common are patients with a supernumerary ring chromosomes 18. High resolution whole genome examination in patients with multiple congenital abnormalities might reveal cytogenetic abnormalities of an unexpected complexity. Results. We report a 24 years old male patient with lower spinal anomalies, hypospadia, bifid scrotum, cryptorchism, anal atresia, kidney stones, urethra anomalies, radial dysplasia, and a hypoplastic thumb. Some of the anomalies overlap with the VACTERL association. Chromosome analysis of cultured peripheral blood lymphocytes revealed an additional ring chromosome in 13% of the metaphases. Both parents had a normal karyotype, demonstrating the de novo origin of this ring chromosome. FISH analysis using whole chromosome paints showed that the additional chromosomal material was derived from chromosome 18. Chromosome analysis of cultured fibroblasts revealed only one cell with the supernumerary ring chromosome in the 400 analyzed. To characterize the ring chromosome in more detail peripheral blood derived DNA was analyzed using SNP-arrays. The array results indicated a 5 Mb gain of the pericentromeric region of chromosome 18q10-q11.2. FISH analysis using BAC-probes located in the region indicated the presence of 6 signals on the r(18) chromosome. In addition, microsatellite analysis demonstrated that the unique supernumerary ring chromosome was paternally derived and both normal copies showed biparental disomy. Conclusions. We report on an adult patient with multiple congenital abnormalities who had in 13% of his cells a unique supernumerary ring chromosome 18 that was composed of 6 copies of the 5 Mb gene rich region of 18q11

Complete APTX deletion in a patient with ataxia with oculomotor apraxia type 1

Background: Ataxia with oculomotor apraxia type 1 is an autosomal-recessive neurodegenerative disorder characterized by a childhood onset of slowly progressive cerebellar ataxia, followed by oculomotor apraxia and a severe primary motor peripheral axonal motor neuropathy. Ataxia with oculomotor apraxia type 1 is caused by bi-allelic mutations in APTX (chromosome 9p21.1). Case presentation: Our patient has a clinical presentation that is typical for ataxia with oculomotor apraxia type 1 with no particularly severe phenotype. Multiplex Ligation-dependent Probe Amplification analysis resulted in the identification of a homozygous deletion of all coding APTX exons (3 to 9). SNP array analysis using the Illumina Infinium CytoSNP-850 K microarray indicated that the deletion was about 62 kb. Based on the SNP array results, the breakpoints were found using direct sequence analysis: c.-5 + 1225_*44991del67512, p.0?. Both parents were heterozygous for the deletion. Homozygous complete APTX deletions have been described in literature for two other patients. We obtained a sample from one of these two patients and characterized the deletion (156 kb) as c.-23729_*115366del155489, p.0?, including the non-coding exons 1A and 2 of APTX. The more severe phenotype reported for this patient is not observed in our patient. It remains unclear whether the larger size of the deletion (156 kb vs 62 kb) plays a role in the phenotype (no extra genes are deleted). Conclusion: Here we described an ataxia with oculomotor apraxia type 1 patient who has a homozygous deletion of the complete coding region of APTX. In contrast to the patient with the large deletion, our patient does not have a severe phenotype. More patients with deletions of APTX are required to investigate a genotype-phenotype effect

Identification of a large rearrangement in CYLD as a cause of familial cylindromatosis

Pathogenic mutations in CYLD can be identified in patients affected with Brooke-Spiegler syndrome, (Familial) Cylindromatosis or multiple familial trichoepithelioma. To date, only technologies which are able to identify small point mutations in CYLD, such as sequence and WAVE analysis, were used. Here we describe the identification of a larger rearrangement identified by Quantitative PCR analysis of CYLD, indicating that a combination of these technologies is necessary when searching for pathogenic mutations in CYLD

Diagnosis and management of Cornelia de Lange syndrome:first international consensus statement

Cornelia de Lange syndrome (CdLS) is an archetypical genetic syndrome that is characterized by intellectual disability, well-defined facial features, upper limb anomalies and atypical growth, among numerous other signs and symptoms. It is caused by variants in any one of seven genes, all of which have a structural or regulatory function in the cohesin complex. Although recent advances in next-generation sequencing have improved molecular diagnostics, marked heterogeneity exists in clinical and molecular diagnostic approaches and care practices worldwide. Here, we outline a series of recommendations that document the consensus of a group of international experts on clinical diagnostic criteria, both for classic CdLS and non-classic CdLS phenotypes, molecular investigations, long-term management and care planning

A Mutation in the Fibroblast Growth Factor 14 Gene Is Associated with Autosomal Dominant Cerebral Ataxia

Hereditary spinocerebellar ataxias (SCAs) are a clinically and genetically heterogeneous group of neurodegenerative disorders for which ⩾14 different genetic loci have been identified. In some SCA types, expanded tri- or pentanucleotide repeats have been identified, and the length of these expansions correlates with the age at onset and with the severity of the clinical phenotype. In several other SCA types, no genetic defect has yet been identified. We describe a large, three-generation family with early-onset tremor, dyskinesia, and slowly progressive cerebellar ataxia, not associated with any of the known SCA loci, and a mutation in the fibroblast growth factor 14 (FGF14) gene on chromosome 13q34. Our observations are in accordance with the occurrence of ataxia and paroxysmal dyskinesia in Fgf14-knockout mice. As indicated by protein modeling, the amino acid change from phenylalanine to serine at position 145 is predicted to reduce the stability of the protein. The present FGF14 mutation represents a novel gene defect involved in the neurodegeneration of cerebellum and basal ganglia

A mutation in the fibroblast growth factor 14 gene is associated with autosomal dominant cerebellar ataxia [corrected]

Hereditary spinocerebellar ataxias (SCAs) are a clinically and genetically heterogeneous group of neurodegenerative disorders for which >/=14 different genetic loci have been identified. In some SCA types, expanded tri- or pentanucleotide repeats have been identified, and the length of these expansions correlates with the age at onset and with the severity of the clinical phenotype. In several other SCA types, no genetic defect has yet been identified. We describe a large, three-generation family with early-onset tremor, dyskinesia, and slowly progressive cerebellar ataxia, not associated with any of the known SCA loci, and a mutation in the fibroblast growth factor 14 (FGF14) gene on chromosome 13q34. Our observations are in accordance with the occurrence of ataxia and paroxysmal dyskinesia in Fgf14-knockout mice. As indicated by protein modeling, the amino acid change from phenylalanine to serine at position 145 is predicted to reduce the stability of the protein. The present FGF14 mutation represents a novel gene defect involved in the neurodegeneration of cerebellum and basal ganglia

Cerebellar Cortical Infarct Cavities : Correlation With Risk Factors and MRI Markers of Cerebrovascular Disease

BACKGROUND AND PURPOSE: Small cerebellar infarct cavities have been recently found on magnetic resonance imaging (MRI) to preferentially involve the cerebellar cortex, but epidemiological studies are lacking. We aimed to determine the prevalence and risk factor profiles of cerebellar cortical infarct cavities (≤1.5 cm) as well as their association with MRI markers of cerebrovascular disease and functioning. METHODS: We analyzed the 1.5 Tesla MRI of 636 patients (mean age, 62±9 years; 81% men) from the Second Manifestations of Arterial Disease-Memory, Depression and Aging (SMART-Medea) study. Logistic regression analyses were performed to estimate the associations of age, sex, vascular risk factors, MRI markers of cerebrovascular disease, and functioning with cerebellar cortical cavities, adjusted for age and sex. RESULTS: Cerebellar cortical infarct cavities occurred on MRI in 10% of patients and were significantly associated with age, intima-media thickness (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.1-3.7), high levels of homocysteinemia (OR, 1.8; 95% CI, 1.0-3.3), cortical infarcts (OR, 2.9; 95% CI, 1.6-5.4), gray matter lacunes of presumed vascular origin (OR, 3.0; 95% CI, 1.6-5.8), brain stem infarcts (OR, 5.1; 95% CI, 1.9-13.6), and decreased brain parenchymal fraction (OR, 0.84; 95% CI, 0.74-0.94), but not with white matter hyperintensities (OR, 1.2; 95% CI, 0.8-1.8) or white matter lacunes of presumed vascular origin (OR, 1.1; 95% CI, 0.5-2.5). They were also associated with worse physical functioning (OR, -2.6; 95% CI, -5.7 to -0.9) but not with mental functioning. CONCLUSIONS: Cerebellar cortical infarct cavities are far more common than previously assumed based on symptomatic case series and are associated with markers of atherothromboembolic cerebrovascular disease

Do Lacunar Infarcts Have Different Aetiologies Risk Factor Profiles of Lacunar Infarcts in Deep White Matter and Basal Ganglia : The Second Manifestations of ARTerial Disease-Magnetic Resonance Study

Background: Evidence suggests that lacunar infarcts have different etiologies, possibly related to their anatomical location and vascular territory. We investigated the risk factor profiles of patients with new lacunar infarcts in the basal ganglia and deep white matter. Methods: Within the Second Manifestations of ARTerial disease-Magnetic Resonance study, a prospective cohort on brain changes on MRI in patients with symptomatic atherosclerotic disease, 679 patients (57 ± 9 years) had vascular screening and MRI at baseline and after a mean follow-up of 3.9 years. We investigated the association between vascular risk factors at baseline and appearance of new lacunar infarcts in the basal ganglia and deep white matter at follow-up. Results: New lacunar infarcts appeared in 44 patients in the basal ganglia and in 37 patients in the deep white matter. In multivariable analysis, older age, history of cerebrovascular disease, and baseline white matter hyperintensity (WMH) volume were associated with increased risk of new lacunar infarcts in both locations. Hyperhomocysteinemia was associated with increased risk of lacunar infarcts in the basal ganglia (relative risk [RR] 2.0; 95% CI 1.0-4.2), whereas carotid stenosis >70% (RR 2.5; 95% CI 1.2-5.0), smoking (per 10 pack-year: RR 1.1; 95% CI 1.0-1.3), hypertension (RR 3.4; 95% CI 1.2-9.7), and progression of WMH volume (RR 2.4; 95% CI 1.1-5.2) were associated with increased risk of lacunar infarcts in the deep white matter. Conclusions: The different risk factor profiles for new lacunar infarcts in basal ganglia and deep white matter indicate different etiologies. The independent association between progression of WMH and new deep white matter lacunar infarcts suggest a common etiology for these radiological abnormalities