[Show abstract][Hide abstract] ABSTRACT: Ring chromosome 15 is a rare disorder, with only a few over 40 cases reported in the literature. There are only two previous reports of cases where patients with ring chromosome 15 have been followed-up.
We report here on the 20-year clinical and cytogenetic follow-up of a patient with a ring chromosome 15. Our patient, a Caucasoid Asian woman, presented with short stature, microcephaly, minor dysmorphic features, hyperextensible knees, generalized hirsutism, café-au-lait and small hypochromic spots spread over her face and the front of her chest and abdomen, dorsolumbar scoliosis and mild intellectual disability. She was followed-up from the age of eight to 28 years. When she was 27 years old, she was reported by her mother to present with compulsive overeating and an aggressive mood when challenged. Karyotyping revealed that the majority of her cells harbored one normal chromosome and one ring chromosome. Silver staining revealed the presence of the nucleolar organizer region in the ring chromosome. Ring loss and/or secondary aberrations exhibited a slight increase over time, from 4.67% in 1989 to 7.67% in 2009, with the presence of two monocentric rings, cells with interlocked rings, a dicentric ring, and broken or open rings. A genome-wide array technique detected a 5.5Mb deletion in 15q26.2.
We observed that some phenotypic alterations in our patient can be associated with gene loss and haploinsufficiency. Other features may be related to different factors, including ring instability and epigenetic factors.
Journal of Medical Case Reports 09/2012; 6(1):283.
[Show abstract][Hide abstract] ABSTRACT: We describe a female patient with developmental delay, dysmorphic features and multiple congenital anomalies who presented a normal G-banded karyotype at the 550-band resolution. Array and multiplex-ligation probe amplification (MLPA) techniques identified an unexpected large unbalanced genomic aberration: a 17.6Mb deletion of 9p associated to a 14.8 Mb duplication of 20p. The deleted 9p genes, especially CER1 and FREM1, seem to be more relevant to the phenotype than the duplicated 20p genes. This study also shows the relevance of using molecular techniques to make an accurate diagnosis in patients with dysmorphic features and multiple anomalies suggestive of chromosome aberration, even if on G-banding their karyotype appears to be normal. Fluorescence in situ hybridization (FISH) was necessary to identify a masked balanced translocation in the patient's mother, indicating the importance of associating cytogenetic and molecular techniques in clinical genetics, given the implications for patient management and genetic counseling.
[Show abstract][Hide abstract] ABSTRACT: Pervasive developmental disorders (PDD) are characterized by comprehensive and qualitative abnormalities affecting three areas of development: reciprocal social interaction, communication, and a repetitive, stereotyped behavioral repertoire, of limited interests. Genetic studies have identified the recurrence of PDD in the same family. The present study aimed to trace the occurrence of signs and symptoms of PDD in the siblings of patients with this diagnosis. The study included 25 subjects from 19 families. Data collection was performed using the Brazilian version of the Autism Screening Questionnaire (ASQ). Two cases of PDD in siblings were confirmed (10.52% of cases): a monozygotic twin brother and the brother of a proband with a diagnosis of Asperger syndrome. Our data indicate higher rates of PDD in siblings than described in the literature (2-6%), close to the findings that suggest a 10% rate of familial recurrence in dizygotic twins. This result provides evidence of possible neurogenetic factors to explain the occurrence of PDD in relatives of the probands assessed and underscores the need to screen not only the child under evaluation, but also their siblings.Keywords: Siblings, genetics, autism spectrum disorders.
Revista de Psiquiatria do Rio Grande do Sul 12/2010; 33(2):116-120.
[Show abstract][Hide abstract] ABSTRACT: We present a 20-year follow-up on a patient with a ring chromosome 14. The ring chromosome was studied by fluorescence in-situ hybridization (FISH), multiplex-ligation probe amplification (MLPA), and genome wide SNP array, and no deletions of chromosome 14 were detected, although the telomeric repeat sequence was absent from the ring chromosome. The patient had skeletal abnormalities, and susceptibility to infections, as well as seizures and retinal pigmentation, which are commonly found in individuals with a ring 14. Our patient corroborates the idea that even when no genes are lost during ring formation, a complete ring chromosome can produce phenotypic alterations, which presumably result from ring instability or gene silencing due to the new chromosomal architecture.
American Journal of Medical Genetics Part A 11/2010; 152A(11):2865-9. · 2.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The most prevalent type of structural variation in the human genome is represented by copy number variations that can affect transcription levels, sequence, structure and function of genes.
In the present study, we used the multiplex ligation-dependent probe amplification (MLPA) technique and quantitative PCR for the detection of copy number variation in 132 intellectually disabled male patients with normal karyotypes and negative fragile-X-testing.
Ten of these patients (7.6%) showed copy number variation in the subtelomeric regions, including deletions and duplications.
Duplications of the SECTM1 gene, located at 17q25.3, and of the FLJ22115 gene, located at 20p13, could be associated with phenotype alterations. This study highlights the relevance in the aetiology of intellectual disability of subtelomeric rearrangements that can be screened by MLPA and other molecular techniques.
Journal of Intellectual Disability Research 10/2010; 54(10):938-42. · 1.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to improve the completion of item 34 on birth certificates at four maternity hospitals in the city of São Paulo, Brazil, in the year 2008. The database of the Municipal Health Department's Information System on Live Births was used to monitor trends in reporting birth defects. An electronic web-based medical record was used to refer indeterminate cases to a leading medical genetics referral center. The electronic medical record contained the patient history, physical examination, and photographs of the newborn. Four maternity hospitals were assessed, with a total of 10,000 births during the year. None of the four hospitals had a staff geneticist. According to the Information System on Live Births, there was an increase in the number of birth defects reported by the four maternity hospitals when compared to previous years and to records for the city of São Paulo as a whole. Based on the findings, the web-based referral and counter-referral method proved efficient.
Cadernos de saúde pública / Ministério da Saúde, Fundação Oswaldo Cruz, Escola Nacional de Saúde Pública 07/2010; 26(7):1383-90. · 0.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The Holt-Oram syndrome (HOS) is an autosomal dominant condition characterized by upper limb and cardiac malformations. Mutations in the TBX5 gene cause HOS and have also been associated with isolated heart and arm defects. Interactions between the TBX5, GATA4 and NKX2.5 proteins have been reported in humans. We screened the TBX5, GATA4, and NKX2.5 genes for mutations, by direct sequencing, in 32 unrelated patients presenting classical (8) or atypical HOS (1), isolated congenital heart defects (16) or isolated upper-limb malformations (7). Pathogenic mutations in the TBX5 gene were found in four HOS patients, including two new mutations (c.374delG; c.678G > T) in typical patients, and the hotspot mutation c.835C > T in two patients, one of them with an atypical HOS phenotype involving lower-limb malformations. Two new mutations in the GATA4 gene were found in association with isolated upper-limb malformations, but their clinical significance remains to be established. A previously described possibly pathogenic mutation in the NKX2.5 gene (c.73C > 7) was detected in a patient with isolated heart malformations and also in his clinically normal father.
Genetics and Molecular Biology 04/2010; 33(2):232-6. · 0.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVE: To identify the main characteristics of the behavioral phenotype of children and adolescents with Prader-Willi syndrome. METHODS: Eleven children and adolescents with clinical and cytogenetic-molecular diagnosis of Prader-Willi syndrome were studied. Data collection was obtained by the Child Behavior Checklist for Ages 6-18 (CBCL/6-18). Bivariate correlations were used to test the association between the analyzed variables, being significant p<0.05. RESULTS: The behavioral profile obtained was considered as clinical in different scales of the CBCL/6-18 tool. A behavioral pattern with high frequency of aggression, rule breaking and opposition was observed. Statistically significant correlations between attention and social problems and between thought problems and breaking rules were identified. CONCLUSIONS: The studied patients represent a group of psychiatric risk, with behavioral changes that, in the long-term, can lead to mood disorders, attention deficit hyperactivity disorder and oppositional defiant behavior, among other disorders.
Revista Paulista de Pediatria 03/2010; 28(1):63-69.
[Show abstract][Hide abstract] ABSTRACT: Ring chromosomes are often associated with abnormal phenotypes due to loss of genomic material and also because of ring instability at mitosis after sister chromatid exchange events. We investigated ring chromosome instability in six patients with ring chromosomes 4, 14, 15, and 18 by examining 48- and 72-h lymphocyte cultures at the first, second and subsequent cell divisions after bromodeoxyuridine incorporation. Although most cells from all patients showed only one monocentric ring chromosome, ring chromosome loss and secondary aberrations were observed both in 48- and 72-h lymphocyte cultures and in metaphase cells of the different cell generations. We found no clear-cut correlation between ring size and ring instability; we also did not find differences between apparently complete rings and rings with genetic material loss. The cytogenetic findings revealed secondary aberrations in all ring chromosome patients. We concluded that cells with ring chromosome instability can multiply and survive in vivo, and that they can influence the patient's phenotype.
[Show abstract][Hide abstract] ABSTRACT: Fetuses exposed to aminopterin during the 8th-9th week of development may show aminopterin embryophathy (AE). Surviving children have a specific phenotype that includes unusual face, skull, and skeletal abnormalities. Fraser et al. [Fraser et al. (1987); Clin Genet 32:28-34] described two children with multiple malformations characteristic of the aminopterin syndrome but without history of exposure to aminopterin in the mothers and suggested that this represents a new syndrome, the aminopterin syndrome-like sine aminopterin (ASSA) syndrome. Here we describe a 9-year-old girl, born to unaffected first cousin parents. She has short stature, microcephaly, broad forehead with high hair implantation; sparse and fine hair, areas of alopecia; arched eyebrows with upturned hair, synophris; ocular hypertelorism, epicanthal folds, palpebral ptosis; oligodontia; low-set and small ears with hypoplasia of antihelices; brachydactyly, clinodactyly of both 4th and 5th fingers; hypoplasia of the 4th metacarpal and clinodactyly of the 4th and 5th toes; overlap of the second over the third toe; bilateral hip luxation; patent foramen ovale; left posterior diaphragmatic hernia, absence of spleen and horseshoe kidney. She, her mother and her brother have a karyotype of 46,XX, with an inv(9)(p12q13) polymorphism. Although this patient has some characteristics did not described before in patients with ASSA such as, palpebral ptosis, oligodontia, left posterior diaphragmatic hernia, absence of spleen, and horseshoe kidney, her phenotype strongly suggest she has the pseudoaminopterin syndrome. However, we do not exclude the possibility that this is a different condition not described previously.
American Journal of Medical Genetics Part A 12/2009; 149A(12):2843-8. · 2.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Rett syndrome (RS) is a severe neurodevelopmental X-linked dominant disorder caused by mutations in the MECP2 gene.
To search for point mutations on the MECP2 gene and to establish a correlation between the main point mutations found and the phenotype.
Clinical evaluation of 105 patients, following a standard protocol. Detection of point mutations on the MECP2 gene was performed on peripheral blood DNA by sequencing the coding region of the gene.
Classical RS was seen in 68% of the patients. Pathogenic point mutations were found in 64.1% of all patients and in 70.42% of those with the classical phenotype. Four new sequence variations were found, and their nature suggests patogenicity. Genotype-phenotype correlations were performed.
Detailed clinical descriptions and identification of the underlying genetic alterations of this Brazilian RS population add to our knowledge of genotype/phenotype correlations, guiding the implementation of mutation searching programs.
Arquivos de neuro-psiquiatria 10/2009; 67(3A):577-84. · 0.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Patients with fragile X syndrome present a variable phenotype, which contributes to the underdiagnosing of this condition. The use of clinical checklists in individuals with intellectual disability can help in selecting patients to be given priority in the molecular investigation of the fragile X mutation in the FMR1 gene. Some features included in checklists are better predictors than others, but they can vary among different populations and with patient age. In the present study, we evaluated 20 features listed in four clinical checklists from the literature, using a sample of 192 Brazilian male patients presenting with intellectual disability (30 positive and 162 negative for fragile X mutation). After statistical analysis, 12 out of the 20 items analyzed showed significant differences in their distributions between the two groups. These features were grouped in a new checklist that can help clinicians in their referral for fragile X testing in patients with developmental delay.
Journal of Intellectual Disabilities 09/2009; 13(3):239-48.
[Show abstract][Hide abstract] ABSTRACT: To translate into Portuguese, back-translate, culturally adapt and validate a screening instrument for pervasive developmental disorder, the Autism Screening Questionnaire, for use in Brazil.
A sample of 120 patients was selected based on three groups of 40: patients with a clinical diagnosis of pervasive developmental disorder, Down syndrome, or other psychiatric disorders. The self-administered questionnaire was applied to the patients' legal guardians. Psychometric measures of the final version of the translated questionnaire were tested.
The score of 15 had sensitivity of 92.5% and specificity of 95.5% as a cut-off point for the diagnosis of pervasive developmental disorder. Internal validity for a total of 40 questions was 0.895 for alpha and 0.896 for KR-20, ranging from 0.6 to 0.8 for both coefficients. Test and retest reliability values showed strong agreement for most questions.
The final version of this instrument, translated into Portuguese and adapted to the Brazilian culture, had satisfactory measurement properties, suggesting preliminary validation proprieties. It was an easy-to-apply, useful tool for the diagnostic screening of individuals with pervasive developmental disorder.
Revista Brasileira de Psiquiatria 04/2009; 31(1):30-3. · 1.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Autosomal-dominant brachydactyly type A2 (BDA2), a limb malformation characterized by hypoplastic middle phalanges of the second and fifth fingers, has been shown to be due to mutations in the Bone morphogenetic protein receptor 1B (BMPR1B) or in its ligand Growth and differentiation factor 5 (GDF5). A linkage analysis performed in a mutation-negative family identified a novel locus for BDA2 on chromosome 20p12.3 that incorporates the gene for Bone morphogenetic protein 2 (BMP2). No point mutation was identified in BMP2, so a high-density array CGH analysis covering the critical interval of approximately 1.3 Mb was performed. A microduplication of approximately 5.5 kb in a noncoding sequence approximately 110 kb downstream of BMP2 was detected. Screening of other patients by qPCR revealed a similar duplication in a second family. The duplicated region contains evolutionary highly conserved sequences suggestive of a long-range regulator. By using a transgenic mouse model we can show that this sequence is able to drive expression of a X-Gal reporter construct in the limbs. The almost complete overlap with endogenous Bmp2 expression indicates that a limb-specific enhancer of Bmp2 is located within the identified duplication. Our results reveal an additional functional mechanism for the pathogenesis of BDA2, which is duplication of a regulatory element that affects the expression of BMP2 in the developing limb.
The American Journal of Human Genetics 04/2009; 84(4):483-92. · 11.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Several authors have attempted to characterize the partial 1q trisomy syndrome, reporting clinical features such as mental retardation, macrocephaly, large fontanels, prominent forehead, broad flat nasal bridge, high-arched palate, micro/retrognathia, low-set ears, and cardiac defects. However, defining the partial trisomy 1q syndrome is difficult, because it is a rare chromosomal abnormality and in most instances the trisomy 1q is combined with partial monosomy of another autosomal segment. We report on the clinical and molecular cytogenetic study of a patient who presents pure partial 1q duplication. This is the first case of pure duplication 1q41-qter in the literature.
American Journal of Medical Genetics Part A 10/2008; 146A(20):2663-7. · 2.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Nonsyndromic syndactyly is a common, heterogeneous hereditary condition of webbed fingers and toes that can be cutaneous or bony, unilateral or bilateral. We describe a patient with complex toe syndactyly and oligodactyly, some interesting skeletal hand findings and atypical facial features without other case like this described before. Cenani-Lenz syndrome (CLS) is a rare disorder with total syndactyly and irregular synostosis of carpal, metacarpal and phalanges, it may involve ulna and radius and digital rays may be absent, some of these were described with atypical facial features and one patient had renal hypoplasia and vertebral anomalies but our patient does not have the oligodactyly or syndactyly of the hands that is consistently present in all patients with CLS. The atypical facial features of our patient resemble Kabuki syndrome but oligodactyly and complex syndactyly have not been described in Kabuki syndrome and this patient has normal intelligence, and extreme eyelid defect (resembling ablepharon). Therefore, for our patient, we suggested to treat in a new condition of limb anomalies and atypical face.
American Journal of Medical Genetics Part A 08/2008; 146A(13):1725-8. · 2.30 Impact Factor