Interstitial deletion of band 3q25

Wisconsin syndrome with brain volume laterality: a case report and review of the literature

Background

Wisconsin syndrome is a congenital anomaly caused by a 3q interstitial deletion. It is associated with characteristic facies and developmental delays. Only 33 cases with a deletion estimated to be in the associated region 3q25 have been reported.

Case report

We present the case of a 5-year-old Japanese girl with a 3q24q25.2 deletion. Her facial features corresponded to the Wisconsin syndrome phenotype, and she exhibited brain volume laterality, which has not been reported previously.

Conclusion

The clinical features of our case may contribute to narrowing down the list of candidate genes of Wisconsin syndrome.

Case report of Chromosome 3q25 deletion syndrome or Mucopolysaccharidosis IIIB

Interstitial deletions of the long arm of chromosome 3 have, to our knowledge, been reported in only eleven patients; detailed genotype- phenotype correlations are not well established. Here we describe a case with interstitial deletion involving 3q25.33 region. Dysmorphic features and developmental delay lead to clinical genetic and enzyme assessment. Low alpha-hexosaminidase level is also noted, which imply Mucopolysaccharidosis(MPS) IIIB.

Dandy-Walker malformation and Wisconsin syndrome: novel cases add further insight into the genotype-phenotype correlations of 3q23q25 deletions

Background

The Dandy-Walker malformation (DWM) is one of the commonest congenital cerebellar defects, and can be associated with multiple congenital anomalies and chromosomal syndromes. The occurrence of overlapping 3q deletions including the ZIC1 and ZIC4 genes in few patients, along with data from mouse models, have implicated both genes in the pathogenesis of DWM.

Methods and results

Using a SNP-array approach, we recently identified three novel patients carrying heterozygous 3q deletions encompassing ZIC1 and ZIC4. Magnetic resonance imaging showed that only two had a typical DWM, while the third did not present any defect of the DWM spectrum. SNP-array analysis in further eleven children diagnosed with DWM failed to identify deletions of ZIC1-ZIC4. The clinical phenotype of the three 3q deleted patients included multiple congenital anomalies and peculiar facial appearance, related to the localization and extension of each deletion. In particular, phenotypes resulted from the variable combination of three recognizable patterns: DWM (with incomplete penetrance); blepharophimosis, ptosis, and epicanthus inversus syndrome; and Wisconsin syndrome (WS), recently mapped to 3q.

Conclusions

Our data indicate that the 3q deletion is a rare defect associated with DWM, and suggest that the hemizygosity of ZIC1-ZIC4 genes is neither necessary nor sufficient per se to cause this condition. Furthermore, based on a detailed comparison of clinical features and molecular data from 3q deleted patients, we propose clinical diagnostic criteria and refine the critical region for WS.

Microdeletion 3q syndrome

The authors present the clinical case of a 5-month-old boy, affected by multimalformative syndrome with features of microdeletion 3q syndrome. In the literature so far, the real incidence is unknown because of its rarity. The goal of this study was to describe the salient findings of this rare malformative syndrome, which needs a multidisciplinary approach. The patient had 3q interstitial chromosome deletion (q22.1-q25.2). He showed the following clinical features: microcephaly, microphthalmia, epicantus inversus, blepharophimosis, palpebral ptosis, short neck with pterygium, brachycephaly, round face, hypotelorism, broad nasal bridge, beaked nose, large and low-set ears, soft cleft palate, retromicrognathia with large mouth, arthrogryposis of the superior limbs and knees in association with clinodactyly, overlapping of second and third digits of both hands and feet, and gastroesophageal reflux. The patient developed physical and motor development delay. He was affected by Dandy-walker malformation, characterized by cerebellum vermis hypoplasia. The placement of the patient in contiguous gene syndrome (Dandy walker syndrome, Pierre-Robin sequence, and Seckel syndrome) was carried out by a multidisciplinary team to have a holistic evaluation of clinical findings. Thanks to this approach, it was possible to establish a complete diagnostic and therapeutic course. The genetic analysis enables to arrange an assistive program. Surgeons' attention was focused on the malformations, which represented an obstacle for normal development and social life.

DIA1R is an X-linked gene related to Deleted In Autism-1

Background

Autism spectrum disorders (ASDs) are frequently occurring disorders diagnosed by deficits in three core functional areas: social skills, communication, and behaviours and/or interests. Mental retardation frequently accompanies the most severe forms of ASDs, while overall ASDs are more commonly diagnosed in males. Most ASDs have a genetic origin and one gene recently implicated in the etiology of autism is the Deleted-In-Autism-1 (DIA1) gene.

Methodology/Principal Findings

Using a bioinformatics-based approach, we have identified a human gene closely related to DIA1, we term DIA1R (DIA1-Related). While DIA1 is autosomal (chromosome 3, position 3q24), DIA1R localizes to the X chromosome at position Xp11.3 and is known to escape X-inactivation. The gene products are of similar size, with DIA1 encoding 430, and DIA1R 433, residues. At the amino acid level, DIA1 and DIA1R are 62% similar overall (28% identical), and both encode signal peptides for targeting to the secretory pathway. Both genes are ubiquitously expressed, including in fetal and adult brain tissue.

Conclusions/Significance

Examination of published literature revealed point mutations in DIA1R are associated with X-linked mental retardation (XLMR) and DIA1R deletion is associated with syndromes with ASD-like traits and/or XLMR. Together, these results support a model where the DIA1 and DIA1R gene products regulate molecular traffic through the cellular secretory pathway or affect the function of secreted factors, and functional deficits cause disorders with ASD-like symptoms and/or mental retardation.

Further molecular and clinical delineation of the Wisconsin syndrome phenotype associated with interstitial 3q24q25 deletions

Deletions of the distal 3q22.3 region encompassing the gene forkhead transcription factor FOXL2 (FOXL2) usually result in intellectual disability (ID) and the highly recognizable blepharophimosis-ptosis-epicanthus inversus syndrome (BPES). We encountered three patients with molecularly defined interstitial deletions distal to the FOXL2 gene. They present with remarkably similar manifestations comprising variable ID, a coarse facial appearance, including prominent nose and eyebrows, hypogonadism and skin pigmentation abnormalities, and they share an approximately 8.8 Mb overlapping 3q24q25 deletion. Interestingly, one of the present patients was described previously in a clinical report with emphasis on her clinical similarity to the Wisconsin syndrome, suggesting that Wisconsin syndrome might be caused by a (micro) deletion within the 3q24q25 region.

Developmental delay and facial dysmorphism in a child with an 8.9 Mb de novo interstitial deletion of 3q25.1-q25.32: Genotype-phenotype correlations of chromosome 3q25 deletion syndrome

Interstitial deletions of the long arm of chromosome 3 are rare and detailed genotype-phenotype correlations are not well established. We report on the clinical, cytogenetic and molecular findings of a 5-year-old patient with a de novo interstitial deletion from 3q25.1 to 3q25.32. Clinical features include relative microcephaly, developmental delay and facial dysmorphism with a coarse face, ptosis, synophrys, epicanthic folds, broad nasal bridge, long philtrum, large mouth with full lips, dysplastic and low-set ears. Revealed by conventional banding techniques, the deleted region of 8.9 Mb was confirmed by fluorescent in situ hybridization (FISH) analyses and array comparative genomic hybridization (array-CGH). To our knowledge, this is the smallest interstitial deletion reported in the 3q25 region. The phenotype of our patient is compared with the 10 previously reported cases implicating the 3q25 region.

Wisconsin syndrome in a patient with interstitial deletion of the long arm of chromosome 3: further delineation of the phenotype

Interstitial deletions of the long arm of chromosome 3 are uncommon. Most cases are related to the blepharophimosis-ptosis-epicanthus inversus syndrome (BPES), which is mapped to 3q23. We report on a case with a de novo chromosomal deletion of 3q23 and 3q25. We review the literature on the reported cases of 3q deletion and find that the condition of our patient is not typical of the BPES. Rather, she shares similarity to a patient with Wisconsin syndrome, first discovered in 1976.