DNA methylation differences in monozygotic twins with Van der Woude syndrome.

Introduction: Van der Woude Syndrome (VWS) is an autosomal dominant disorder responsible for 2% of all syndromic orofacial clefts (OFCs) with IRF6 being the primary causal gene (70%). Cases may present with lip pits and either cleft lip, cleft lip with cleft palate, or cleft palate, with marked phenotypic discordance even among individuals carrying the same mutation. This suggests that genetic or epigenetic modifiers may play additional roles in the syndrome's etiology and variability in expression. We report the first DNA methylation profiling of 2 pairs of monozygotic twins with VWS. Our goal is to explore epigenetic contributions to VWS etiology and variable phenotypic expressivity by comparing DNAm profiles in both twin pairs. While the mutations that cause VWS in these twins are known, the additional mechanism behind their phenotypic risk and variability in expression remains unclear. Methods: We generated whole genome DNAm data for both twin pairs. Differentially methylated positions (DMPs) were selected based on: (1) a coefficient of variation in DNAm levels in unaffected individuals < 20%, and (2) intra-twin pair absolute difference in DNAm levels >5% (delta beta > | 0.05|). We then divided the DMPs in two subgroups for each twin pair for further analysis: (1) higher methylation levels in twin A (Twin A > Twin B); and (2) higher methylation levels in twin B (Twin B >Twin A). Results and Discussion: Gene ontology analysis revealed a list of enriched genes that showed significant differential DNAm, including clef-associated genes. Among the cleft-associated genes, TP63 was the most significant hit (p=7.82E-12). Both twin pairs presented differential DNAm levels in CpG sites in/near TP63 (Twin 1A > Twin 1B and Twin 2A < Twin 2B). The genes TP63 and IRF6 function in a biological regulatory loop to coordinate epithelial proliferation and differentiation in a process that is critical for palatal fusion. The effects of the causal mutations in IRF6 can be further impacted by epigenetic dysregulation of IRF6 itself, or genes in its pathway. Our data shows evidence that changes in DNAm is a plausible mechanism that can lead to markedly distinct phenotypes, even among individuals carrying the same mutation.

A genetic linkage study in Brazil identifies a new locus for persistent developmental stuttering on chromosome 10.

Although twin, adoption, and family studies demonstrate that genetic factors are involved in the origins of stuttering, the mode of transmission of the disorder in families is not well defined and stuttering is considered a genetically complex trait. We performed a genome-wide linkage scan in a group of 43 Brazilian families, each containing multiple cases of persistent developmental stuttering. Linkage analysis under a dominant model of inheritance generated significant evidence of linkage in two Brazilian families, with a combined maximum single-point LOD score of 4.02 and a multipoint LOD score of 4.28 on chromosome 10q21. This demonstrated the presence of a novel variant gene at this locus that predisposes individuals to stuttering, which provides an opportunity to identify novel genetic mechanisms that underlie this disorder.

Assessment of clinical scoring systems for the diagnosis of Williams-Beuren syndrome.

Williams-Beuren syndrome (WBS) is a genetic disorder characterized by physical and intellectual developmental delay, associated with congenital heart disease and facial dysmorphism. WBS is caused by a microdeletion on chromosome 7 (7q11.23), which encompasses the elastin (ELN) gene and about 27 other genes. The gold standard for WBS laboratory diagnosis is FISH (fluorescence in situ hybridization), which is very costly. As a possible alternative, we investigated the accuracy of three clinical diagnostic scoring systems in 250 patients with WBS diagnosed by FISH. We concluded that all three systems could be used for the clinical diagnosis of WBS, but they all gave a low percentage of false-positive (6.0-9.2%) and false-negative (0.8-4.0%) results. Therefore, their use should be associated with FISH testing.

Sulcus vocalis: evidence for autosomal dominant inheritance.

We found evidence of autosomal dominant hereditary transmission of sulcus vocalis. Four dysphonic patients from three generations of the same family were submitted to videolaryngoscopic examination (three patients) and to direct laryngoscopy (one patient) to diagnose the hoarseness. Sulcus vocalis was diagnosed in all four patients. The finding of four affected individuals in three generations, with vertical transmission affecting man and women, is more consistent with autosomal dominant inheritance pattern; it is an etiological model that we propose for the sulcus vocalis in this pedigree.

Oropharyngeal dysphagia and language delay in partial trisomy 9p: case report.

The phenotype of partial trisomy 9p includes global developmental delay, microcephaly, bulbous nose, downturned oral commissures, malformed ears, hypotonia, and severe cognitive and language disorders. We present a case report and a comparative review of clinical findings on this condition, focusing on speech-language development, cognitive abilities and swallowing evaluation. We suggest that oropharyngeal dysphagia should be further investigated, considering that pulmonary and nutritional disorders affect the survival and quality of life of the patient. As far as we know, this is the first study of a patient with partial trisomy 9p described with oropharyngeal dysphagia.

MOMO syndrome associated with autism: a case report.

This is a case report of macrosomia, obesity, macrocephaly and ocular abnormalities (MOMO syndrome) associated with autism. Studies on genetic or environmental syndromes associated with autism can provide genetic markers or uncover relevant events, and are very important for the definition of autism subgroups in future molecular research.

Diagnosis of Smith-Lemli-Opitz syndrome by ultraviolet spectrophotometry

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder due to an inborn error of cholesterol metabolism, characterized by congenital malformations, dysmorphism of multiple organs, mental retardation and delayed neuropsychomotor development resulting from cholesterol biosynthesis deficiency. A defect in 3ß-hydroxysteroid-delta7-reductase (delta7-sterol-reductase), responsible for the conversion of 7-dehydrocholesterol (7-DHC) to cholesterol, causes an increase in 7-DHC and frequently reduces plasma cholesterol levels. The clinical diagnosis of SLOS cannot always be conclusive because of the remarkable variability of clinical expression of the disorder. Thus, confirmation by the measurement of plasma 7-DHC levels is needed. In the present study, we used a simple, fast, and selective method based on ultraviolet spectrophotometry to measure 7-DHC in order to diagnose SLOS. 7-DHC was extracted serially from 200 æl plasma with ethanol and n-hexane and the absorbance at 234 and 282 nm was determined. The method was applied to negative control plasma samples from 23 normal individuals and from 6 cases of suspected SLOS. The method was adequate and reliable and 2 SLOS cases were diagnosed

Identity by descent and candidate gene mapping of Richieri-Costa and Pereira syndrome.

The Richieri-Costa-Pereira syndrome is a rare autosomal recessive disorder characterized by short stature, Robin sequence, cleft mandible, pre/postaxial anomalies and clubfoot. Of 15 families reported with this disorder 14 are from Brazil suggesting a founder effect. We studied 15 families using identity-by-descent as a hypothesis to attempt gene localization We have examined through linkage analysis 497 polymorphic-markers and also performed direct sequencing of exons for 10 candidate genes selected on the basis of their expression in the developing mandible and limb. No evidence for allele sharing at any locus tested or mutations in candidate genes was found. Additional higher resolution mapping, new families and other candidate genes might improve future chances of gene identification.

Diagnosis of Smith-Lemli-Opitz syndrome by ultraviolet spectrophotometry.

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder due to an inborn error of cholesterol metabolism, characterized by congenital malformations, dysmorphism of multiple organs, mental retardation and delayed neuropsychomotor development resulting from cholesterol biosynthesis deficiency. A defect in 3 -hydroxysteroid-delta7-reductase (delta7-sterol-reductase), responsible for the conversion of 7-dehydrocholesterol (7-DHC) to cholesterol, causes an increase in 7-DHC and frequently reduces plasma cholesterol levels. The clinical diagnosis of SLOS cannot always be conclusive because of the remarkable variability of clinical expression of the disorder. Thus, confirmation by the measurement of plasma 7-DHC levels is needed. In the present study, we used a simple, fast, and selective method based on ultraviolet spectrophotometry to measure 7-DHC in order to diagnose SLOS. 7-DHC was extracted serially from 200 l plasma with ethanol and n-hexane and the absorbance at 234 and 282 nm was determined. The method was applied to negative control plasma samples from 23 normal individuals and from 6 cases of suspected SLOS. The method was adequate and reliable and 2 SLOS cases were diagnosed.

Metacarpophalangeal pattern profile in Marfan syndrome and Marfan-like patients.

Marfan syndrome (MFS) is an autosomal dominant trait due to mutations in the fibrillin gene (FBN1). The MFS expressivity is variable, and its diagnosis relies completely on clinical criteria. Atypical cases and Marfan-like (marfanoid) clinical presentations are commonly found. The metacarpophalangeal pattern profile (MCPP), a radiological method in which the 19 tubular hand bones are assessed, has been used in the diagnosis of various syndromes. To investigate whether the MCPP was adequate to discriminate between MFS and Marfan-like subjects, we studied 38 patients who were referred to our service because they had an MFS diagnosis, diagnostic hypothesis, or differential diagnosis or had arachnodactyly with dolichostenomelia. Two groups were formed: 1) MFS: 21 patients with a mean age of 18.3 (10.8 S.D.) years and 2) Marfan-like syndromes: 16 patients who did not meet the current criteria, with a mean age of 14.6 (4.6 S.D.) years. The MCPP was performed in each case following the classical technique, and a characteristic mean profile was obtained for group I (MFS), with Z scores ranging from 0.69 to 2.73 (1.80+/-0.50; mean+/-S.D.). In group I, three cases had no correlation with the typical MFS pattern. In group II, three cases had an MFS pattern. The correlation with the mean MCPP of MFS permitted the differential diagnosis of MFS and marfanoid syndromes with 86% sensitivity, 81% specificity, and 86% positive and 81% negative predictive values. The results suggest that MCPP can be used effectively as an auxiliary tool in the nosology of these conditions and, because there is no change in MCPP with age, can be helpful in early diagnosis.

Macrosomia, obesity, macrocephaly and ocular abnormalities (MOMO syndrome) in two unrelated patients: delineation of a newly recognized overgrowth syndrome.

We describe 2 unrelated patients, a boy and a girl, with an overgrowth syndrome and the following common characteristics: macrocrania, obesity, ocular abnormalities (retinal coloboma and nystagmus), downward slant of palpebral fissures, mental retardation, and delayed bone maturation. Both cases are of sporadic occurrence with no consanguinity between the parents. We suggest that this syndrome is due to a new autosomal dominant mutation and propose to designate it with the acronym of "MOMO syndrome" (Macrosomia, Obesity, Macrocrania, Ocular anomalities.

Cytogenetic evidence of involvement of chromosome regions 15q12 and 12q15 in conditions with associated overgrowth.

Syndromes with associated overgrowth are poorly understood. Besides their mode of inheritance, nothing is known regarding the basic genetic alterations that lead to their abnormal phenotypic manifestations. The chromosome localization of the genes involved remains unknown for this group of syndromes, with the only exception being the Wiedemann-Beckwith syndrome.

[Macrosomia, macrocrania and motor disorders in childhood, Sotos syndrome (McKusick 11755): report of 7 cases and review of clinical aspects of 198 reported cases]. / Macrossomia, macrocrania e incoordenação motora da infância: síndrome de Sotos (McKusick 11755): estudo de 7 casos e revisão de aspectos clínicos de 198 casos publicados.

Children with Sotos syndrome have growth acceleration, macrocephaly, acromegaloid features and delay in neuropsychomotor development during infancy. Syndrome delineation and differential diagnosis are based on evaluation of phenotypic characteristics and evolutive history of the patients. Seven patients with this syndrome are reported, and the relative occurrence of the phenotypic characteristics present in 198 reported cases are reviewed. Motor difficulties present in those patients during early infancy are responsible for the poor performance on IQ tests. Oriented stimulation should be encouraged in order to help the affected children to overcome their initial difficulties and to achieve normal scholarity and life performance.

Macrocephaly, multiple lipomas, and hemangiomata (Bannayan-Zonana syndrome): genetic heterogeneity or autosomal dominant locus with at least two different allelic forms?

We describe a boy with mild manifestations of the Bannayan-Zonana syndrome (BZS): large scaphocephalic head with marked frontal bossing, hypertrophy on the right side of the body, large and irregular café-au-lait spots, and cutaneous telangiectasia on large parts of the body and a cavernous hemangioma on the internal side of the left leg; soft cutaneous masses were present in the left axilla and inner part of the left arm; hypotonia and mild neurologic dysfunction were also present. BZS is reported as an autosomal dominant condition with variable expressivity; analysis of our data and those reported in the literature suggest that the interfamilial variability observed might represent different allelic mutations, or genetic heterogeneity.