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PubMed1996

Autism in Angelman syndrome: a population-based study.

The aim of this study was to examine the prevalence of angelman syndrome in prepubertal school-aged children and analyze its comorbidity with autistic disorder. A clinical/psychiatric evaluation of a population-based sample of 6- to 13-year-old mentally retarded children with active epilepsy was performed. Four individuals in a total population of almost 49,000 children conformed to the clinical diagnosis of Angelman syndrome. Two of these had a typical microdeletion at chromosome 15q11-13. The minimum prevalence of Angelman syndrome was estimated at 0.008% (1: 12,000) in the examined age group. All 4 children with Angelman syndrome met full behavioral criteria for the diagnosis of autistic disorder/childhood autism. It is concluded that Angelman syndrome is uncommon, but more frequent than previously estimated. The diagnosis should be considered in all patients with combined autistic disorder, severe mental retardation, and epilepsy. The implications of the possible association of Angelman syndrome and autism are discussed.

Adolescent↗
PubMed2006

Identification of a new in-frame deletion of six amino acids in ribosomal protein S19 in a patient with Diamond-Blackfan anemia.

Ribosomal protein S19 (RPS19) is currently the only gene associated with Diamond-Blackfan anemia (DBA), a rare congenital pure red cell aplasia characterized by normochromic macrocytic anemia, reticulocytopenia, and normocellular bone marrow with a selective deficiency of erythroid precursors. RPS19 is mutated in 25% of DBA patients, but its role in DBA pathogenesis remains elusive. We have identified a novel heterozygous microdeletion in RPS19 in a DBA patient presenting with profound anemia after birth. The deletion of 18 nucleotides (233-250; A in start codon is +1) in exon 4 leads to the elimination of 6 amino acids 78IYGGRQ83, affecting the most conserved stretch of three amino acids (YGG) in RPS19. The mutated allele was not detected in the patient's family members, indicating de novo mutation. Both alleles were expressed at the same level. Using an immunofluorescence technique, the mutated RPS19 protein localized to nucleoli, and its intracellular distribution did not differ from the wild-type RPS19. The deletion of only a few amino acids of this protein with a preserved reading frame is rare, and this type of a mutation could be very helpful in further experiments to define the role of the RPS19 protein in DBA pathogenesis.

Anemia, Diamond-Blackfan↗
PubMed2005

COMT Val108/158 Met modifies mismatch negativity and cognitive function in 22q11 deletion syndrome.

BACKGROUND: Microdeletions at 22q11.2 greatly increase the risk of schizophrenia in early adulthood (relative risk approximately 25-30). We hypothesized that before the onset of schizophrenia, individuals with 22q11DS would manifest specific cognitive and neurophysiological anomalies (endophenotypes) in common with individuals at high risk for schizophrenia in the general population. We further predicted that the catechol-O-methyltransferase Val(108/158)Met polymorphism, located within the deleted chromosomal segment, would modify the severity of endophenotypic features. METHODS: 22q11DS adolescents and young adults (aged 13-21) were compared with age- and IQ-matched control subjects on measures that are associated with risk of idiopathic schizophrenia. RESULTS: 22q11DS subjects displayed poorer verbal working memory and expressive language performance than control subjects. Auditory mismatch negativity (MMN) event-related potentials were reduced at frontal electrodes but were intact at temporal sites. Presence of the COMT(108/158)Met allele on the single intact chromosome 22 was associated with more marked MMN amplitude reduction and poorer neuropsychological performance. Neither COMT Val(108/158)Met allele influenced psychiatric symptoms. CONCLUSIONS: 22q11DS is associated with neurodevelopmental characteristics that are similar to idiopathic schizophrenia. The COMT Val(108/158)Met polymorphism modifies the severity of endophenotypes for schizophrenia, indicating that impaired catecholamine regulation contributes to neuropsychiatric risk in 22q11DS.

Acoustic Stimulation↗
PubMed2005

Neurological aspects of the Angelman syndrome.

Angelman syndrome (AS) has emerged as an important neurogenetic syndrome due to its relatively high prevalence and easier confirmation of the diagnosis by improved genetic testing. In infancy, nonspecific clinical features of AS pose diagnostic challenges to the neurologist and these include any combination of microcephaly, seizure disorder, global developmental delay or an ataxic/hypotonic cerebral palsy-like picture. In later childhood, however, absent speech, excessively happy behavior, ataxia and jerky movements usually present as a recognizable clinical syndrome. Brain MRI shows nonspecific or normal findings but occasionally the characteristic EEG patterns alone can lead to the correct diagnosis. The physical, clinical and behavioral aspects appear to be attributable to localized CNS dysfunction of the ubiquitin ligase gene, UBE3A, located at 15q11.2. In certain brain regions, UBE3A normally has mono-allelic expression from the maternally derived chromosome 15. Several distinct genetic mechanisms can inactivate or disrupt the maternally derived UBE3A: chromosome microdeletions, paternal uniparental disomy, imprinting defects and intragenic UBE3A mutations. Those with the deletion type of AS are the most prevalent (about 70% of cases) and appear to have a more severe clinical phenotype. The unique epileptic patterns and distinct behavioral features may be related to multiple actions of UBE3A, possibly occurring during, as well as after, the time of neuronal development.

Adolescent↗
PubMed2005

Del 1p36 syndrome: a newly emerging clinical entity.

Monosomy 1p36 is a recently delineated contiguous gene syndrome, which is now considered to be the most common subtelomeric microdeletion syndrome. From the recent literature it appears as if 1p36 deletions account for 0.5-1.2% of idiopathic mental retardation. The deletions can be detected by high resolution cytogenetic studies in a minority of patients, and fluorescence in situ hybridisation (FISH) is required in most. The deletions' parent of origin seems still unclear, although in one large series it was shown to be maternal. 1p36 deletion syndrome is characterized by distinct craniofacial features, associated with developmental delay/mental retardation, hypotonia, muscle hypotrophy, seizures, brain abnormalities, and heart defects. To help child neurologists and other professionals in the recognition of this emerging and common chromosomal syndrome, we have reviewed published articles on patients with this deletion.

Abnormalities, Multiple↗
PubMed2005

Central precocious puberty in a girl with Williams syndrome: the result of treatment with GnRH analogue.

Williams syndrome (WS) is a well-known microdeletion syndrome characterized by specific facial features, retardation in growth and development, typical personality and cardiac defects. Poor growth potential is further affected by central precocious puberty (CPP) which is frequent in these patients. A WS patient with CPP is presented, whose pubertal development and bone age progression were arrested by administration of GnRH analogues. The case is reported to discuss the role of GnRH analogues for management of CPP in patients with WS.

Child↗
PubMedDate not supplied

Detection and delineation of an unusual 17p11.2 deletion by array-CGH and refinement of the Smith-Magenis syndrome minimum deletion to approximately 650 kb.

Smith-Magenis syndrome (SMS) is a multiple congenital anomaly/mental retardation syndrome and it is characterized by an interstitial deletion of chromosome 17p11.2. SMS patients have a distinct phenotype which is believed to be caused by haploinsufficiency of one or more genes in the associated deleted region. Five non-deletion patients with classical phenotypic features of SMS have been reported with mutations in the retinoic acid induced 1 (RAI1) gene, located within the SMS critical interval. Happloinsufficiency of the RAI1 gene is likely to be the responsible gene for the majority of the SMS features, but other deleted genes in the SMS region may modify the overall phenotype in the patients with 17p11.2 deletions. SMS is usually diagnosed in the clinical genetic setting by FISH analysis using commercially available probes. We detected a submicroscopic deletion in 17p11.2 using array-CGH with a resolution of approximately 1 Mb in a patient with the SMS phenotype, who was not deleted for the commercially available SMS microdeletion FISH probe. Delineation of the deletion was performed using a 32K tiling BAC-array, containing 32,500 BAC clones. The deletion in this patient was size mapped to 2.7 Mb and covered the RAI1 gene. This case enabled the refinement of the SMS minimum deletion to approximately 650 kb containing eight putative genes and one predicted gene. In addition, it demonstrates the importance to investigate deletion of RAI1 in SMS patients.

Abnormalities, Multiple↗
PubMed2005

European Cytogeneticists Association Register of Unbalanced Chromosome Aberrations (ECARUCA); an online database for rare chromosome abnormalities.

During recent years a considerable improvement in diagnostic techniques has enabled cytogeneticists to find more and smaller chromosomal aberrations. However, accurate clinical knowledge about rare chromosome disorders is frequently lacking, mostly due to a significant decline in publishable cases. On the other hand, there is an increasing demand from parents and physicians for reliable information. In order to improve the quality and the quantity of data available, we designed a new database named the European Cytogeneticists Association Register of Unbalanced Chromosome Aberrations (ECARUCA) at http://www.ecaruca.net. This Internet-database contains cytogenetic and clinical data of patients with rare chromosome abnormalities, including microscopically visible aberrations, as well as microdeletions and -duplications. Cases with certain breakpoints collected in the Zurich Cytogenetic Database were transferred to ECARUCA. The advantages of ECARUCA compared to existing sources are that ECARUCA is interactive, dynamic and has long-term possibilities to store cytogenetic, molecular and clinical data. Professionals can login to submit new cases and perform searches in the database through the Internet. Currently the database contains 1500 unique chromosomal aberrations from almost 4000 patients. A frequent submission of new data ensures the up-to-date quality of the collection. Individual parent accounts allow parents to inform the ECARUCA team about the follow-up of their child. The ECARUCA database provides health care workers with accurate information on clinical aspects of rare chromosome disorders. Additionally, detailed correlations between chromosome aberrations and their phenotypes are of invaluable help in localising genes for mental retardation and congenital anomalies.

Chromosome Aberrations↗
PubMed2006

Clinical presentation of a variant of Axenfeld-Rieger syndrome associated with subtelomeric 6p deletion.

We report a 22-year-old female with a variant of the Axenfeld-Rieger Syndrome (ARS) and discuss its relation with the subtelomeric 6p deletion. An ARS variant has been described in two familial cases of Axenfeld-Rieger Anomaly (ARA) featuring specific extra ocular manifestations-hypertelorism, midface hypoplasia, mild sensorial deafness, hydrocephaly, psychomotor delay and flattened femoral epiphyses. We proposed that this set of characteristics represents a separate syndrome within the ARS. On the other hand, there have been reported four cases with cryptic de novo pure 6pter microdeletions detected by specific subtelomeric probes in patients with ARS characteristics. We describe a 6pter deletion detected by SNP genotyping and confirmed by FISH and MLPA involving the FOXC1 gene in a patient with ocular and systemic findings that fit perfectly with the variant mentioned above. We conclude that the ARS variant belongs to the ARS phenotypic spectrum, which includes flattened femoral epiphyses as a feature.

Abnormalities, Multiple↗
PubMed2005

Cytogenetic analysis of azoospermic patients: karyotype comparison of peripheral blood lymphocytes and testicular tissue.

OBJECTIVE: The objective was to compare the results of a complete chromosomal, genetic and histological investigation in 13 azoospermic men with the results of the intracytoplasmic sperm injection (ICSI) procedure. STUDY DESIGN: Peripheral blood samples were used for the measurement of follicle-stimulating hormone (FSH) levels, chromosomal analysis, microdeletions in the azoospermia factor (AZF) region of the Y chromosome and cystic fibrosis transmembrane conductance regulator (CFTR) mutation analysis. Testicular tissue was used for histological scoring and cytogenetic evaluation. RESULTS: Peripheral blood cytogenetic analysis revealed a normal male karyotype in all cases. Chromosomal analysis from testicular tissue revealed a mosaicism for the terminal deletion of chromosome 22 with a breakpoint site at 22q13 in one patient with congenital bilateral absence of the vas deferens (CBAVD). Deletions in the AZFa, ATFb, and AZFc regions were not detected. The CFTR mutational analysis showed normal results in all patients. CONCLUSIONS: Cytogenetic evaluation of testicular tissue should be performed in non-obstructive and obstructive azoospermic patients as well as in patients with multiple failed IVF and recurrent spontaneous abortion.

Adult↗
PubMed2004

Analysis of the DAZ gene family in cryptorchidism and idiopathic male infertility.

OBJECTIVE: To investigate whether partial deletions of the DAZ gene family on the Y chromosome are associated with cryptorchidism, similar to that found for complete AZF deletions. DESIGN: Prospective study. SETTING: University hospital. PATIENT(S): A total of 193 azoospermic and severely oligozoospermic men: 95 with a history of cryptorchidism and 98 classified as idiopathic. INTERVENTION(S): A two-part study for Y chromosome microdeletions was performed: a polymerase chain reaction (PCR)-based analysis for complete AZF deletions and partial DAZ gene analysis by PCR-restriction digestion assay for single-family variants. MAIN OUTCOME MEASURE(S): Presence and type of AZF deletions and number of DAZ genes present. RESULT(S): The frequency of complete AZF deletions was similar in idiopathic (13.3%) and cryptorchid men (11.6%), but partial DAZ deletions were found only in infertile subjects without cryptorchidism (7.1%). The testicular phenotype was similar in men with complete AZF deletions and partial DAZ deletions, therefore the contribution of the other AZF genes in determining the spermatogenic impairment is still unclear. CONCLUSION(S): Our findings suggest that the loss of only some copies of DAZ is sufficient to lead to severe male infertility, but it is not a frequent finding in cryptorchid men.

Chromosomes, Human, Y↗
PubMed2004

Sperm tail agenesis in a case of consanguinity.

OBJECTIVE: To report a case of 100% teratozoospermia in a patient whose family history presented a high degree of consanguinity. DESIGN: Case report. SETTING: University-based andrology clinic. PATIENT(S): A 27-year-old man undergoing infertility evaluation. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Serum hormone analysis, standard (World Health Organization) semen quality evaluation, sperm ultrastructure, lymphocytic karyotype, and polymerase chain reaction screening for Y chromosome microdeletions in peripheral blood. RESULT(S): One hundred percent teratozoospermia characterized by shape alterations of the heads and tail agenesis on standard morphology evaluation, which was confirmed using electron microscopy. CONCLUSION(S): A case of familial infertility in a consanguineous patient characterized by morphological abnormalities of spermatozoa such as tail agenesis, chromatin subcondensation, and residual cytoplasmic droplets.

Adult↗
PubMed2004

Etiology of azoospermia in 100 consecutive nonvasectomized men.

History was taken systematically for 100 azoospermic, nonvasectomized men referred consecutively to a Danish fertility clinic. The men were examined by ultrasound, and their blood samples were analyzed for karyotype, Y microdeletions, and cystic fibrosis transmembrane conductance regulator gene mutations. In 29% of patients, the condition could be explained by genetic abnormalities; in 22%, by diseases or external influence; and in 27%, by former cryptorchidism. The azoospermic condition remained unexplained in only 22%.

Cryptorchidism↗
PubMed2025

Pathogenic XPO1 variants cause a dominant neurodevelopmental disorder.

PURPOSE: XPO1 functions in key cellular processes, including nucleo-cytoplasmic export and mitosis. The gene is deleted in a subset of patients with the 2p15p16.1 microdeletion syndrome; however, no monogenic XPO1-related disorder has been described to date. METHODS: We collected clinical data of individuals with de novo XPO1 variants through online matchmaking. We used Drosophila to study XPO1 function in development and habituation learning. RESULTS: A total of 22 individuals met the criteria to be included in the main study cohort. Of these, half have putative loss-of-function variants, and half have coding variants (10 missense and 1 in-frame deletion variant). We found an overlapping phenotype, consistent with a monogenic neurodevelopmental disorder. We demonstrate XPO1 functions in development by ubiquitous and neuron-specific knockdown in Drosophila. GABAergic neuron specific knockdown flies demonstrated impaired habituation. CONCLUSION: Our results establish XPO1 as a novel dominant monogenic neurodevelopmental disorder gene and demonstrate a central role for XPO1 in development.

Exportin 1 Protein↗
PubMed2006

Upper airway asymmetry in velo-cardio-facial syndrome.

OBJECTIVE: Various forms of asymmetry have been recognized as a feature of velo-cardio-facial syndrome (VCFS). This study was implemented to determine the frequency of anatomic and functional asymmetry of the velum, pharynx and larynx in children with VCFS. METHODS: Individuals with VCFS underwent prospective, blinded analysis by an expert panel who assessed the velum, pharynx and larynx with multi-view videofluoroscopy (MVF) and nasopharyngolaryngoscopy (NPL). The VCFS group was compared to an age-matched group of normal individuals. Eight different parameters were assessed in both groups for functional and anatomic symmetry including: velar elevation, adenoid size, posterior pharyngeal wall size, carotid pulsations, epiglottis size and shape, arytenoid size, true vocal cord size and true vocal cord motion. RESULTS: One hundred and twenty-one subjects with VCFS and 20 normal individuals underwent examination. Children with VCFS showed significantly more asymmetry compared to the normal group (69% versus 20%, P=0.01) with greatest differences seen with palatal motion, posterior pharyngeal wall size and epiglottis shape. On average, subjects with VCFS had three asymmetric parameters versus one parameter in the normal group. CONCLUSION: Asymmetric development of the pharynx and larynx in children with VCFS appears to be a distinct clinical feature of this syndrome. This finding may provide an important diagnostic clue for patients presenting with subtle features of the 22q11.2 microdeletion. These developmental abnormalities may increase the risk of speech impairment, aspiration and airway obstruction in affected individuals.

Adolescent↗
PubMed2005

Cutis laxa in Kabuki make-up syndrome.

Kabuki make-up syndrome (KMS; OMIM#147920) is a multiple congenital anomalies/mental retardation syndrome of unknown cause, first described independently by Niikawa and Kuroki. It is characterized by a peculiar facial appearance, mild to moderate mental retardation, skeletal abnormality, joint laxity, short stature, and unusual dermatoglyphic patterns. Several additional malformations (eg, cleft palate), cardiovascular defects, genitourinary and gastrointestinal tract anomalies, otologic and ophthalmologic abnormalities, and recurrent infections are also frequently present. It is mostly sporadic, although some familial cases have been reported. Inheritance is thought to be autosomal dominant or X-linked recessive; several chromosomal abnormalities have been found, but none of them seems to be specific to KMS. The fact that the majority of patients are sporadic and show a wide spectrum of clinical features rules out the hypothesis that KMS is a condition with a microdeletion involving several contiguous genes. We recently observed an Italian boy with typical KMS associated with cutis laxa, which, to our knowledge, is an uncommon finding in KMS, never reported in more than 350 KMS cases previously described in the literature.

Abnormalities, Multiple↗
PubMed2026

Postzygotic biallelic inactivation of FDFT1 underlies solitary lesion formation in porokeratosis of Mibelli.

BACKGROUND: Porokeratosis reflects clonal expansion of keratinocytes with biallelic inactivation of mevalonate-cholesterol biosynthesis pathway genes. In disseminated porokeratosis (DP), lesions arise through independent somatic second hits in carriers of heterozygous germline pathogenic variants, whereas porokeratosis of Mibelli (PM) is usually solitary, and its molecular basis remains incompletely defined. OBJECTIVE: To elucidate the molecular basis of solitary PM. METHODS: We analyzed blood and lesional epidermis from seven patients with solitary PM within a 156-patient porokeratosis cohort using deep sequencing, copy-number/SNP profiling, and methylation analysis. RESULTS: Solitary PM plaques were larger and more irregular than the annular DP lesions. No pathogenic germline variants were detected in MVK, PMVK, MVD, FDPS, or FDFT1. Three patients had somatic biallelic genetic inactivation of FDFT1 through putative deleterious variants and/or focal microdeletions. The remaining four showed FDFT1 promoter hypermethylation with loss of heterozygosity (LOH) at the FDFT1 locus due to copy-neutral LOH or a monoallelic 8p deletion, consistent with early monoallelic epigenetic silencing, followed by genetic loss of the remaining active allele. In one patient, part of the plaque expanded centrifugally over 7.5 years. CONCLUSION: Solitary PM can be driven by postzygotic, lesion-restricted, biallelic inactivation of FDFT1 through genetic or epigenetic mechanisms within a single epidermal clone, promoting clonal expansion. This model may explain the tendency toward solitary PM lesions. The low probability of acquiring postzygotic biallelic inactivation without germline predisposition may underlie solitary PM and suggest a low recurrence risk for offspring, unlike DP driven by germline heterozygosity.

General dermatology↗
PubMed2006

Targeted genomic microarray analysis for identification of chromosome abnormalities in 1500 consecutive clinical cases.

OBJECTIVE: To assess the yield of array-based comparative genomic hybridization. STUDY DESIGN: The results of array comparative genomic hybridization were collected on 1500 consecutive clinical cases sent to our laboratory for a variety of developmental problems. Confirmation fluorescence in situ hybridization of metaphase or interphase cells, depending on the aberration, was performed. RESULTS: Of the 1500 cases, 134 (8.9%) showed an abnormality: 36 (2.4%) showed polymorphisms or familial variants, 14 (0.9%) showed alterations of unknown clinical significance, and 84 (5.6%) showed clinically relevant genomic alterations. These included subtelomeric deletions and unbalanced rearrangements, microdeletions and reciprocal duplications, rare abnormalities, and low-level trisomy mosaicism. CONCLUSIONS: A targeted array detects a substantial proportion of abnormalities even in those patients who have already had extensive cytogenetic and/or fluorescence in situ hybridization testing. This study, although not a controlled ascertainment of subjects with specific selection criteria, accurately reflects the reality of clinical cytogenetic practice and provides an estimate of the cytogenetic abnormalities that can be identified with a targeted microarray in a diagnostic laboratory. Microarray analysis likely doubles the current yield of abnormal results detected by conventional cytogenetic analysis.

Child↗