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Orsetta Zuffardi

Publications and source records attributed to Orsetta Zuffardi.

At least 19 recordsLinked to original sources
PubMed2025

AUTS2-related syndrome: Insights from a large European cohort.

PURPOSE: AUTS2-related syndrome is characterized by developmental delay, autism spectrum disorder, and intellectual disability. From alternative promoters, AUTS2 encodes 2 distinct long and short isoforms encoding a putative transcriptional activator. METHODS: Through a European collaborative study, we collected clinical and genotype data on the largest AUTS2-related syndrome cohort of 58 patients harboring genomic rearrangements or single-nucleotide variants (SNVs). RESULTS: Pathogenic SNVs were recurrently found in individuals from different countries, suggesting mutational hotspots. Independent of the underlying defect at the AUTS2 locus, we observed that autistic behavior, hyperactivity, learning difficulties, and speech delay are common features of AUTS2-related syndrome. Among patients with SNVs, individuals carrying pathogenic variants affecting both longer and shorter AUTS2 transcripts showed a recognizable phenotype with microcephaly, brachycephaly, microretrognathia, broad nasal base, and anteverted nares. Behavioral disorders were more common in patients with variants affecting only the longer isoform. Arthrogryposis and stiff movements were only observed in patients with SNVs. CONCLUSION: This study provides a comprehensive clinical characterization of AUTS2-related syndrome, reveals few genotype-phenotype correlations, and suggests that the disruption of the 2 distinct AUTS2 transcripts has a different impact on the clinical phenotype.

Humans↗
PubMed2007

A patient with duplication (7)(p22.1pter) characterized by array-CGH.

Approximately 40 patients with terminal duplication of the distal short arm of chromosome 7 have been reported, the smallest being dup(7)(p21). We report here on a patient with a smaller duplication, dup(7)(p22.1), detected on G-banding and characterized by array-CGH. We establish phenotype-karyotype correlations with the reported patients with other 7p duplications.

Abnormalities, Multiple↗
PubMed2007

13q Deletion and central nervous system anomalies: further insights from karyotype-phenotype analyses of 14 patients.

BACKGROUND: Chromosome 13q deletion is associated with varying phenotypes, which seem to depend on the location of the deleted segment. Although various attempts have been made to link the 13q deletion intervals to distinct phenotypes, there is still no acknowledged consensus correlation between the monosomy of distinct 13q regions and specific clinical features. METHODS: 14 Italian patients carrying partial de novo 13q deletions were studied. Molecular-cytogenetic characterisation was carried out by means of array-comparative genomic hybridisation (array-CGH) or fluorescent in situ hybridisation (FISH). RESULTS: Our 14 patients showed mental retardation ranging from profound-severe to moderate-mild: eight had central nervous system (CNS) anomalies, including neural tube defects (NTDs), six had eye abnormalities, nine had facial dysmorphisms and 10 had hand or feet anomalies. The size of the deleted regions varied from 4.2 to 75.7 Mb. CONCLUSION: This study is the first systematic molecular characterisation of de novo 13q deletions, and offers a karyotype-phenotype correlation based on detailed clinical studies and molecular determinations of the deleted regions. Analyses confirm that patients lacking the 13q32 band are the most seriously affected, and critical intervals have been preliminarily assigned for CNS malformations. Dose-sensitive genes proximal to q33.2 may be involved in NTDs. The minimal deletion interval associated with the Dandy-Walker malformation (DWM) was narrowed to the 13q32.2-33.2 region, in which the ZIC2 and ZIC5 genes proposed as underlying various CNS malformations are mapped.

Abnormalities, Multiple↗
PubMed2006

A novel interstitial deletion in Xq25, identified by array-CGH in a patient with Lowe syndrome.

The oculocerebrorenal syndrome of Lowe (OCRL) (MIM:309000) is an X-linked multisystemic disorder affecting the eyes, nervous system and kidneys due to mutations in OCRL1 gene. The gene contains 24 exons, and encodes a 105kDa phosphatydylinositol 4,5-biphosphate [PtdIns(4,5)P(2)] 5-phosphatase localized primarily in the trans-Golgi network and the lysosomes. The large majority of the OCRL1 mutations producing Lowe syndrome are either missense mutations localized mainly in the catalytic domain or non-sense/frameshift mutations resulting in truncated proteins. Rarely, in about 6% of the cases, the disease results from large gene deletions occurring in the 5' part of the gene. Here we report a new case of a patient with Lowe syndrome due to a deletion of about 4Mb, encompassing the OCRL1 gene, detected by PCR and CGH array. The mother was carrier of the same deletion.

Chromosome Deletion↗
PubMed2006

Cortical dysplasia of the left temporal lobe might explain severe expressive-language delay in patients with duplication of the Williams-Beuren locus.

We report on a new duplication case of 7q11.23, reciprocal of the Williams-Beuren (WB) deletion. The patient, a 13-year-old girl, was ascertained within an array-CGH screening of patients with epilepsy and neuronal migration defects. Similarly to the first reported patient, she showed serious difficulties in expressive language in the absence of severe mental retardation and marked dysmorphic features. Magnetic resonance imaging (MRI) of the brain revealed an abnormal development of the cerebral cortex in the left temporal lobe, which showed a simplified gyral pattern, and increased cortical thickness. This finding, which might explain poor language development, suggests that the WB critical region might harbour a dosage-sensitive gene controlling the molecular machinery of neuronal migration, with regional specificity and lateralization. It will be important to confirm our findings in newly diagnosed patients with dup(7)(q11.23). We expect to detect many more patients with the same duplication using widespread clinical implementation of high-resolution genome analysis.

Chromosomes, Human, Pair 7↗
PubMed2006

Malpuech syndrome: broadening the clinical spectrum and molecular analysis by array-CGH.

We report on a patient with mental and growth retardation, bilateral cleft lip and palate, hypertelorism, ptosis, hearing loss and mild epispadias, suggestive of Malpuech syndrome. High-resolution karyotype and microarray-CGH using an oligonucleotide array with 75Kb oligo's were normal, excluding Wolf-Hirschhorn syndrome. Long-term follow-up revealed psychiatric manifestations starting at young age.

Abnormalities, Multiple↗
PubMed2006

Identification and molecular modelling of a novel familial mutation in the SRY gene implicated in the pure gonadal dysgenesis.

SRY gene is responsible for initiating male sexual differentiation. The protein encoded by SRY contains a homeobox (HMG) domain, which is a DNA-binding domain. Mutations of the SRY gene are reported to be associated with XY pure gonadal dysgenesis. The majority of these are de novo mutations affecting only one individual in a family. Only a small subset of mutations is shared between the father and one or more of his children. Most of these familial mutations are localized within the HMG box and only two are at the N-terminal domain of the SRY protein. Herein, we describe a young girl with pure gonadal dysgenesis and her father carrying a novel familial mutation in the SRY gene at codon number 3. This mutation is resulting in a serine (S) to leucine (L) substitution. The secondary structure of the SRY protein was carried out by protein modelling studies. This analysis suggests, with high possibility, that the N-terminal domain of the SRY protein, where we found the mutation, could form an alpha-helix from amino acid in position 2 to amino acid in position 13. The secondary structure prediction and the chemical properties of serine to leucine substitution stands for a potential disruption of this N-terminal alpha-helix in the SRY protein. This mutation could have some role in impeding the normal function of the SRY protein.

Adolescent↗
PubMed2006

Subtelomeric trisomy 21q: a new benign chromosomal variant.

The diagnosis of a subtelomeric rearrangement has immediate impact on counseling, particularly in the case of familial rearrangements. However, the existence of subtelomeric imbalances with absent phenotypic effects may hamper genetic counseling, particularly when the rearrangement has not been previously described. We report on a new subtelomeric polymorphism, consisting of a familial subtelomeric rearrangement of chromosome 19 resulting in distal trisomy for 21q, detected in a child with Angelman Syndrome (AS) due to an UBE3A mutation. This report shows that new, previously unknown, benign subtelomeric variants may complicate the correct clinical diagnosis.

Angelman Syndrome↗
PubMed2006

A locus for familial skewed X chromosome inactivation maps to chromosome Xq25 in a family with a female manifesting Lowe syndrome.

In mammals, X-linked gene products can be dosage compensated between males and females by inactivation of one of the two X chromosomes in the developing female embryos. X inactivation choice is usually random in embryo mammals, but several mechanisms can influence the choice determining skewed X inactivation. As a consequence, females heterozygous for X-linked recessive disease can manifest the full phenotype. Herein, we report a family with extremely skewed X inactivation that produced the full phenotype of Lowe syndrome, a recessive X-linked disease, in a female. The X chromosome inactivation studies detected an extremely skewed inactivation pattern with a ratio of 100:0 in the propositus as well as in five out of seven unaffected female relatives in four generations. The OCRL1 "de novo" mutation resides in the active paternally inherited X chromosome. X chromosome haplotype analysis suggests the presence of a locus for the familial skewed X inactivation in chromosome Xq25 most likely controlling X chromosome choice in X inactivation or cell proliferation. The description of this case adds Lowe syndrome to the list of X-linked disorders which may manifest the full phenotype in females because of the skewed X inactivation.

Chromosomes, Human, X↗
PubMed2006

Chromosomal rearrangements in Xq and premature ovarian failure: mapping of 25 new cases and review of the literature.

BACKGROUND: Chromosomal rearrangements in Xq are frequently associated with premature ovarian failure (POF) and have defined a POF 'critical region'. Search for genes responsible for the disorder has been elusive. METHODS: We report mapping of novel breakpoints of X;autosome-balanced translocations and interstitial deletions and a review of published X chromosome rearrangements. RESULTS: All the novel POF-associated rearrangements were mapped outside and often very distant from genes. The majority mapped to a gene-poor region in Xq21. In the same region, deletions were reported in women who apparently did not have problems conceiving. Expression analysis of genes flanking breakpoints clustered in a 2-Mb region of Xq21 failed to demonstrate ovary-specific genes. CONCLUSIONS: Our results excluded most of the possible explanations for the POF phenotype and suggested that POF should be ascribed to a position effect of the breakpoints on flanking genes. We also showed that while the X breakpoint may affect X-linked genes in the distal part of Xq, from Xq23 to Xq28, interruption of the critical region in Xq21 could be explained by a position effect of the Xq critical region on genes flanking the autosomal breakpoints.

Adult↗
PubMed2006

A 46,X,inv(Y) young woman with gonadal dysgenesis and gonadoblastoma: cytogenetics, molecular, and methylation studies.

Cytogenetic analysis of a young woman with gonadal dysgenesis and bilateral gonadoblastoma shared a male karyotype with a rearranged Y chromosome, interpreted as a pericentric inversion. The breakpoints, defined by fluorescent in situ hybridization (FISH), were located on the very distal short arm on band Yp11.31 and in the middle of the Yq12 long arm heterochromatic region. FISH analysis documented that the short arm breakpoint was 93 Kb distal to SRY and disrupted the CD99 gene, which was transposed to the distal portion of Yq12. The proposita's phenotype was similar to that of XY individuals with gonadal dysgenesis but without signs of Ullrich-Turner syndrome. There were no mutations in the SRY gene. Cytogenetic analysis in the proposita's father showed mosaicism of a normal Y chromosome and several different rearrangements, such as deletion of a heterochromatin portion at band Yq12.2, a fragile site at the same band, structural rearrangements between the Y-chromosome and other autosomes, Y-chromosome aneuploidies, and "Premature Centromere Division" (PCD) anomaly. The proposita's inverted Y chromosome appears to have originated from paternal Y chromosome instability. The patient's female phenotype could be due to SRY CpG methylation-mediated positional effects (PEV).

Adolescent↗
PubMed2005

Direct duplication 12p11.21-p13.31 mediated by segmental duplications: a new recurrent rearrangement?

We describe the characterization of an interstitial duplication of 12p, dup(12)(p11.21p13.31), by array-CGH and FISH in a patient with mental retardation and dysmorphic features. The sequence analysis of the breakpoints revealed the presence of homologous low copy repeats (LCRs) flanking the duplication region, thus suggesting that they have mediated the rearrangement. Pip-maker analysis showed that a third cluster of homologous LCRs lie distally to the two mediating the 12p duplication. We hypothesize that this duplication might be a new recurrent rearrangement and that, thanks to the different orientations of the homologous regions lying within each cluster, the three clusters are responsible for at least some of the several 12p aneuploidies reported in the literature such as direct and inverted duplications, deletions and supernumerary analphoid chromosomes. Moreover, we excluded that polymorphic inversions between these three clusters are present in the normal population.

Abnormalities, Multiple↗
PubMed2005

Loss-of-function mutation of the AF9/MLLT3 gene in a girl with neuromotor development delay, cerebellar ataxia, and epilepsy.

The human AF9/MLLT3 gene is a common fusion partner for the MLL gene in translocations t(9;11)(p22;q23) associated with acute myeloid leukemia and acute lymphocytic leukemia. The exact function of the gene is still unknown, although a mouse knock-out model points to a role as a controller of embryo patterning. We report the case of a constitutional translocation t(4;9)(q35;p22) disrupting the AF9/MLLT3 gene in a girl with neuromotor development delay, cerebellar ataxia and epilepsy. Array-CGH analysis at 1 Mbase resolution did not reveal any additional deletions/duplications. We hypothesize a loss-of-function mutation of the AF9/MLLT3 gene, and a possible role for the FAT gene on chromosome 4, in the genesis of the proband's severe neurological phenotype.

Base Sequence↗
PubMed2005

Microphthalmia with linear skin defects (MLS) syndrome: clinical, cytogenetic, and molecular characterization of 11 cases.

The microphthalmia with linear skin defects (MLS) syndrome (MIM 309801) is a severe and rare developmental disorder, which is inherited as an X-linked dominant trait with male lethality. In the vast majority of patients, this syndrome is associated with terminal deletion of the Xp22.3 region. Thirty-five cases have been described to date in the literature since the first description of the syndrome in the early 1990s. We now report on the clinical, cytogenetic, and molecular characterization of 11 patients, 7 of whom have not been described previously. Seven of these patients have chromosomal abnormalities of the short arm of the X-chromosome, which were characterized and defined by fluorescence in situ hybridization (FISH) analysis. Intriguingly, one of the patients displays an interstitial Xp22.3 deletion, which to the best of our knowledge is the first reported for this condition. Finally we report on the identification and molecular characterization of four cases with clinical features of MLS but apparently normal karyotypes, verified by FISH analysis using genomic clones spanning the MLS minimal critical region, and with genome-wide analysis using a 1 Mb resolution BAC microarray. These patients made it possible to undertake mutation screening of candidate genes and may prove critical for the identification of the gene responsible for this challenging and intriguing genetic disease.

Abnormalities, Multiple↗
PubMed2005

Reciprocal translocations: a trap for cytogenetists?

We report four cases of subjects with phenotypic abnormalities and mental retardation associated with apparently balanced translocations, two inherited and two de novo, which showed, by molecular analysis, a hidden complexity. All the cases have been analyzed with different molecular techniques, including array-CGH, and in two of them the translocation breakpoints have been defined at the level of base pairs via studies in somatic hybrids containing single derivative chromosomes. We demonstrated that all the translocations were in fact complex rearrangements and that an imbalance was present in three of them, thus accounting for the phenotypic abnormalities. In one case, a Prader-Willi subject, we were not able to determine the molecular cause of his phenotype. This study, while confirming previous data showing unexpected complexity in translocations, further underscores the need for molecular investigations before taking for granted an apparently simple cytogenetic interpretation.

Abnormalities, Multiple↗
PubMed2005

8.5 Mb deletion at distal 5p in a male ascertained for azoospermia.

We report on a 5p- azoospermic male not showing the clinical features diagnostic for the cri-du-chat syndrome but for a breathy, raspy voice. The 5p deletion breakpoint, determined by fluorescent in situ hybridization (FISH) analysis with BAC clones, maps 8.5 Mb far from the short arm telomere in 5p15.31. Genotype/phenotype correlations in this subject, including his neuropsychological assessment, led us to define that the gene for the cat-like cry and one gene responsible for mild mental retardation with speech delay map both in the distal 8.5 Mb of chromosome 5 short arm.

Adult↗
PubMed2005

A 2.3 Mb duplication of chromosome 8q24.3 associated with severe mental retardation and epilepsy detected by standard karyotype.

Chromosome duplications are found in about 2% of subjects with a typical chromosomal phenotype but their frequency is likely to be higher, as suggested by the first array-CGH data. According to the orientation of the duplicated segment, duplications may be in tandem or inverted. The latter are usually associated with a distal deletion. We studied a de novo 2.3 Mb inverted duplication of 8q24.3 without apparently associated deletion in a subject with profound psychomotor retardation, idiopathic epilepsy and growth delay. In spite of its small size, the presence of the rearrangement was suspected on standard karyotypes (approximately 400 bands) and later confirmed by Fluorescent in situ hybridization (FISH) analysis. We hypothesize that the GRINA gene, a glutamate binding subunit of NMDA receptor ion channel lying within the duplicated segment, may be responsible for the epilepsy. This paper confirms that small subtelomeric de novo duplications may be responsible for mental retardation, facial dysmorphisms and/or congenital malformations, although their presence may be overlooked by FISH analysis.

Child↗