BACKGROUND: Patients with 22q11.2 microduplication syndrome exhibit a high degree of phenotypic heterogeneity and incomplete penetrance, making prenatal diagnosis challenging due to phenotypic variability. This report aims to raise awareness among prenatal diagnostic practitioners regarding the variant\'s complexity, providing a basis for prenatal genetic counseling.
METHODS: Family and clinical data of 31 fetuses with 22q11.2 microduplications confirmed by chromosomal microarray between June 2017 and June 2023 were considered.
RESULTS: Primary prenatal ultrasound features of affected fetuses include variable cardiac and cardiovascular anomalies, increased nuchal translucency (≥3 mm), renal abnormalities, and polyhydramnios. More than half of fetuses considered showed no intrauterine manifestations; therefore, prenatal diagnostic indicators were primarily advanced maternal age or high-risk Down syndrome screening. Most fetuses had microduplications in proximal or central 22q11.2 regions, with only three cases with distal microduplications. Among parents of fetuses considered, 87% (27/31) continued the pregnancy. During follow-up, 19 cases remained clinically asymptomatic.
CONCLUSIONS: Nonspecific 22q11.2 microduplication features in fetuses and its mild postnatal disease presentation highlight the need to cautiously approach prenatal diagnosis and pregnancy decision-making. Increased clinical efforts should be made regarding providing parents with specialized genetic counseling, long-term follow-up, and fetal risk information.

BACKGROUND: With advances in prenatal diagnostic techniques, chromosomal microdeletions and microduplications have become the focus of prenatal diagnosis. 7q partial monosomy or trisomy due to a deletion or duplication of the 7q end is relatively rare and usually originates from parents carrying a balanced translocation.
METHODS: Noninvasive prenatal screening (NIPT) showed a fetus with partial deletion and duplication of chromosome 7q. It was not possible to determine whether the fetus was normal.
METHODS: Conventional chromosome G-banding and chromosome microarray analysis (CMA) were performed on fetal amniotic fluid samples and parental peripheral blood samples.
METHODS: The pregnant women were given detailed genetic counseling by clinicians.
RESULTS: The fetal karyotype was 46, XY on conventional G-banding analysis. The CMA test results showed a deletion of approximately 7.8 Mb in the 7q36.1q36.3 region and a duplication of 6.6Mb in the 7q35q36.1 region. The parents\' karyotype analysis and CMA results were normal, indicating a new mutation.
CONCLUSIONS: CMA molecular diagnostic analysis can effectively detect chromosomal microdeletions or microduplications, clarify the relationship between fetal genotype and clinical phenotype, and provide a reference for prenatal diagnosis of chromosomal microdeletion-duplication syndrome.

BACKGROUND: Trisomy 20p is a rare genetic condition caused by a duplication of the short arm of chromosome 20.
METHODS: We employed clinical observation and molecular genetic testing (SNP microarray), to study identical twin males with an unknown dysmorphic syndrome. We conducted a literature review of trisomy 20p and collated the clinical and molecular genetic findings on 20 affected subjects reported since 2000.
RESULTS: Identical twin males, whose prenatal course was complicated by a twin-to-twin transfusion, manifested profound language and neurocognitive delays as well as distinctive facial dysmorphisms when evaluated at 2 years of age. SNP microarray identified identical duplications of 20p13 with no other chromosomal aberrations. A literature survey of 20p trisomy syndrome identified 20 other examples of this condition reported since 2000, which we collated with 33 summarized by Sidwell et al. (2000). Within the combined total of 55 affected individuals, we found a distinctive clinical phenotype that provides insight on the effects of abnormal dosage of genes in 20p13. These loci include FAM110A (OMIM 611393), ANGPT4 (OMIM 603705), RSPO4 (OMIM 610573), PSMF1 (OMIM 617858), SNPH (OMIM 604942), SDCBP2 (OMIM 617358), FKBP1A (OMIM 186945), TMEM74B, C20orf202, and RAD21L1 (OMIM 619533). Gene profiling highlighted that syntaphilin (SNPH) is highly expressed in mammalian brain, where it is considered critical for mitochondrial transport in neuronal axons, and to directly influence axonal morphogenesis and function.
CONCLUSIONS: We propose that abnormal activity of syntaphilin engendered by the trisomy is primarily responsible for the language, neurocognitive, and gross motor delays reported in individuals with 20p trisomy. Additional studies, for example, characterization of cerebral organoids generated from affected patients may help to better understand this condition, and potentially suggest rational remedies to improve the lives of affected individuals and their families.

Orthodenticle homeobox 2 (OTX2) is a known oncogenic driver of medulloblastoma. Germline duplication of 14q22.3 including OTX2 is a rare condition reported in patients with combined pituitary hormone deficiency, oculo-auriculo-vertebral spectrum, and hemifacial microsomia. There has been one previously published case of a patient carrying a 14q22.3 duplication that included OTX2 with hemifacial microsomia who also developed medulloblastoma. Here, we present a case of a 6-year-old girl with a history of delayed development who was diagnosed with medulloblastoma. Genetic evaluations revealed that she inherited a germline duplication of 14q22.3, which included OTX2. This genetic alteration was passed down from her mother, who also had a history of delayed development. Results from other genetic testing, including exome sequencing, fragile X syndrome, and mtDNA testing, were negative/normal. This is the second report of a 14q22.3 duplication that included OTX2 in a patient with medulloblastoma. Further studies are necessary to establish a clear association.

Duplications of the 3q29 cytoband are rare chromosomal copy number variations (CNVs) (overlapping or recurrent ~1.6 Mb 3q29 duplications). They have been associated with highly variable neurodevelopmental disorders (NDDs) with various associated features or reported as a susceptibility factor to the development of learning disabilities and neuropsychiatric disorders. The smallest region of overlap and the phenotype of 3q29 duplications remain uncertain. We here report a French cohort of 31 families with a 3q29 duplication identified by chromosomal microarray analysis (CMA), including 14 recurrent 1.6 Mb duplications, eight overlapping duplications (>1 Mb), and nine small duplications (<1 Mb). Additional genetic findings that may be involved in the phenotype were identified in 11 patients. Focusing on apparently isolated 3q29 duplications, patients present mainly mild NDD as suggested by a high rate of learning disabilities in contrast to a low proportion of patients with intellectual disabilities. Although some are de novo, most of the 3q29 duplications are inherited from a parent with a similar mild phenotype. Besides, the study of small 3q29 duplications does not provide evidence for any critical region. Our data suggest that the overlapping and recurrent 3q29 duplications seem to lead to mild NDD and that a severe or syndromic clinical presentation should warrant further genetic analyses.

The short arm of chromosome 16 and especially the region 16p13.11 is a chromosome region where many structural variants, especially deletions and duplications, can be observed. Although deletions of this region are clinically well defined, duplications are rare, and so far, there is no established clinical consensus in regard with its clinical picture, and especially the dysmorphic perspective of the disease is far from being clear. A 5-year-and-2-month-old patient who presented with epilepsy, autism and late speech onset complaints was evaluated in our genetics department. On physical examination, unilateral preauricular skin tag and upslanting palpebral fissures were noted. Microarray analysis was performed and reported as ([hg19]: 16p13.11 (14.897.804-16.730.375) x3). The literature review revealed only a few reports about the syndrome, but some dysmorphological findings appear to recur in different reports, which enables a possible characterization. Dysmorphic findings were discussed.

OBJECTIVE: We report a prenatal case of male fetus with a 2q13 deletion and an Xq27.3q28 duplication, presenting nasal bone dysplasia by ultrasound examination. And we compare the similarities of clinical features of cases consisting of similar 2q deletion and Xq duplication.
METHODS: A 30-year-old woman was referred for prenatal diagnosis and genetic counseling at 24 weeks of gestation. Prenatal ultrasound showed nasal bone dysplasia of the fetus. Amniocentesis revealed the karyotype of the fetus as 46, XY and the results of chromosomal microarray analysis was arr[GRCh37] 2q13(110467258-111370025)x1, arr[GRCh37]Xq27.3q28(144050780-149748782)x2. The parents both have normal karyotypes. The couple chose to continue the pregnancy and finally delivered a male infant at 39 weeks of gestation. His weight was 2850 g and length was 50 cm. Physical examination of the newborn revealed no apparent anomalies. Until the boy was one year old, there was no abnormalities in his growth and development. The long-term follow-up till adulthood for the healthy infant is necessary.
CONCLUSIONS: The development of CMA plays a critical role in prenatal diagnosis and genetic counseling for unidentified chromosomal anomalies. More clinical information and further studies of patients with these anomalies will identify the pathogenicity of the involving genes and improve the understanding of the phenotype-genotype correlation.

The 22q11 region is prone to generating recurring Copy Number Variations (CNVs) as a result of the large numbers of Low Copy Repeats (LCRs). Typical duplications encompass the LCR-A-to-D region but atypical duplications of various sizes have also been reported. These duplications are responsible for highly variable phenotypes with incomplete penetrance and expressivity, which is challenging for adequate genetic counselling, especially in the prenatal period. To better delineate prenatal phenotypes associated with these CNVs, we report here a clinical and molecular description of twelve cases (9 foetuses and 3 deceased new-borns babies) carrying recurrent 22q11 duplications (diagnosed via aCGH), along with a review of the existing literature. 22q11 duplications were inherited from an apparently healthy parent in almost 60% of the cases. Other CNVs were diagnosed for 8% of the cases. Increased nuchal translucency and cardiac anomalies (CHD) were the most prominent phenotypes observed, along with mild renal and skeletal anomalies. Duplications encompassing the LCR-C-to-D region (and the CRKL gene) seemed more likely to generate CHDs and renal malformations. Cleft lip/palate were observed in foetuses with duplications encompassing the LCR-A-to-B region or the SPECC1L gene, as previously suggested. However, genotype-phenotype correlations remain difficult to ascertain. Second-hit point variants, epigenetic or environmental variations could play a role in the phenotypic variability of 22q11 duplications, but remain a challenge for assessment in the short period of pregnancy.

The terminal 14q32 duplication has been reported often in association with other cytogenetic abnormalities, and individuals with this specific duplication showed varying degrees of developmental delay/intellectual disability (DD/ID) and growth retardation (GR), and distinct facial dysmorphisms. Herein, based on the limited cases of terminal duplication of 14q32 known to date, we present new affected siblings presenting with DD/ID, GR, and facial dysmorphism, as well as cerebral infarction caused by recurrent de novo der(14)t(14;14)(p11.2;q32.1) leading to terminal duplication of 14q32. We used coverage analysis generated via duo exome sequencing, performed chromosomal microarray (CMA) as a confirmatory test, and compared our findings with those reported previously. Coverage analysis generated via duo exome sequencing revealed a 17.2 Mb heterozygous duplication at chromosome 14q32.11-q32.33 with a Z ratio ranging between 0.5 and 1 in the proband and her elder brother. As a complementary method, CMA established a terminal duplication described as the arr[hg19]14q32.11q32.33(90,043,558_107,258,824)x3 in the proband and her elder brother; however, the parents and other siblings showed normal karyotyping and no abnormal gain or loss of CMA results. Five candidate genes, BCL11B, CCNK, YY1, DYNC1H1, and PACS2, were associated with the clinical phenotypes in our cases. Although the parents had normal chromosomes, two affected cases carrying terminal duplication of 14q32 can be explained by gonadal mosaicism. Further studies are needed to establish the association between cerebrovascular events and terminal duplication of chromosome 14q32, including investigation into the cytogenetics of patients with precise clinical descriptions.

Copy number variants (CNVs) play an important role in the genetic underpinnings of neuropsychiatric/neurodevelopmental disorders. The chromosomal region 16p11.2 (BP4-BP5) harbours both deletions and duplications that are associated in carriers with neurodevelopmental and neuropsychiatric conditions as well as several rare disorders including congenital malformation syndromes. The aim of this article is to provide a review of the current knowledge of the diverse neurodevelopmental disorders (NDD) associated with 16p11.2 deletions and duplications reported in published cohorts. A literature review was conducted using the PubMed/MEDLINE electronic database limited to papers published in English between 1 January 2010 and 31 July 2020, describing 16p11.2 deletions and duplications carriers\' cohorts. Twelve articles meeting inclusion criteria were reviewed from the 75 articles identified by the search. Of these twelve papers, eight described both deletions and duplications, three described deletions only and one described duplications only. This study highlights the heterogeneity of NDD descriptions of the selected cohorts and inconsistencies concerning accuracy of data reporting.