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.

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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.

OBJECTIVE: To explore the characteristics of a fetus with chromosome 1p36 deletion syndrome and 3p26.3p25.2 duplication.
METHODS: A pregnant woman who had attended the Genetic Counseling Clinic of Linyi People\'s Hospital on February 22, 2022 and her fetus were selected as the study subjects. Clinical data were collected. Chromosomal karyotyping, fluorescence in situ hybridization (FISH) and chromosomal microarray analysis (CMA) were carried out for the prenatal diagnosis.
RESULTS: Ultrasonography at 24th gestational week revealed that the fetus had ventricular septal defect, single umbilical artery, and slight widening of left lateral ventricle (12 mm). The woman was found to have a karyotype of 46,XX,t(1;3)(p36.22;p25.2), and the result of FISH was t(1;3)(3pter+,1qter+;1pter+,3qter+). The fetus was found to have a karyotype of 46,X?,add(1)(p36), and CMA confirmed that it has a 9.0 Mb deletion at 1p36.33p36.22 and a 12.6 Mb duplication at 3p26.3p25.2. Combining the maternal karyotype, the molecular karyotype of the fetus was determined as 46,X?,der(1)t(1;3)(p36.22;p25.2)mat.arr[hg19]1p36.33p36.22(849467_9882666)×1, 3p26.3p25.2(61892_12699607)×3, with the former known to be associated with 1p36 deletion syndrome.
CONCLUSIONS: The fetus was diagnosed with 1p36 deletion syndrome, and its 1p36.33p36.22 deletion and 3p26.3p25.2 duplication had both derived from the balanced translocation carried by its mother.

The rare genetic variants 16p11.2 duplication and 16p11.2 deletion have opposing effects on brain structure and function, yet are associated with broadly similar clinical phenotypes that include autism, intellectual impairment, psychiatric illness, and motor difficulties. In recent years, studies have identified subtle distinctions between the phenotypic effects of 16p11.2 duplication and 16p11.2 deletion with respect to patterns of autism, intellectual impairment, and psychiatric illness. However, although divergent phenotypic findings in some motor domains have been reported, no study has yet made a comprehensive comparison of motor difficulties between 16p11.2 deletion and 16p11.2 duplication carriers to elucidate points of convergence and divergence. We sought to make such a comparison in a group of 133 16p11.2 deletion carriers, 122 duplication carriers, and 388 familial controls, hypothesizing that motor impairment would overall be greater in deletion than duplication carriers. In a series of regression models, we found that 16p11.2 deletion status tended to predict greater impairment along indices of gross motor function, but less impairment along indices of fine motor function. These findings point to a potential pattern of performance difficulties that could be investigated in future studies. Elucidating motor differences between 16p11.2 duplication and 16p11.2 deletion carriers may help in understanding the complex effect of 16p11.2 copy number variation and other rare genetic causes of autism.

BACKGROUND: Distal Xq28 duplication, or int22h1/int22h2-mediated Xq28 duplication syndrome, leads to cognitive impairment, neurobehavioral issues, and facial dysmorphisms. Existing literature has limited information on clinical traits and penetrance.
METHODS: We identified cases of distal Xq28 duplication (chrX: 154,126,575-154,709,680, GRCh37/hg19) through a review of clinical records and microarray reports from five centers, encompassing both postnatal and prenatal cases, with no prior family knowledge of the duplication.
RESULTS: Our search found 47 cases across 26 families, with duplications ranging from 208 to 935 Kb. In total, 8 out of 26 index cases featured a 200-300 kb partial duplication, mainly from Armenian/Caucasian Jewish backgrounds. Most prenatal cases showed no major fetal ultrasound malformations. Of cases with known inheritance mode (15 out of 26), maternal inheritance was more common (80%). The study identified seven male carriers of the duplication from six unrelated families, indicating partial penetrance in males.
CONCLUSIONS: Our study provides key insights into distal Xq28 duplication. Most prenatal tests showed no major fetal ultrasound issues. Maternal inheritance was common, with unaffected mothers. In the postnatal group, a balanced gender distribution was observed. Among male family members, two fathers had ADHD, one was healthy, and one brother had mild symptoms, indicating partial penetrance in males.

Aneuploidy is widely observed in both unicellular and multicellular eukaryotes, usually associated with adaptation to stress conditions. Chromosomal duplication stability is a tradeoff between the fitness cost of having unbalanced gene copies and the potential fitness gained from increased dosage of specific advantageous genes. Trypanosomatids, a family of protozoans that include species that cause neglected tropical diseases, are a relevant group to study aneuploidies. Their life cycle has several stressors that could select for different patterns of chromosomal duplications and/or losses, and their nearly universal use of polycistronic transcription increases their reliance on gene expansion/contraction, as well as post-transcriptional control as mechanisms for gene expression regulation. By evaluating the data from 866 isolates covering seven trypanosomatid genera, we have revealed that aneuploidy tolerance is an ancestral characteristic of trypanosomatids but has a reduced occurrence in a specific monophyletic clade that has undergone large genomic reorganization and chromosomal fusions. We have also identified an ancient chromosomal duplication that was maintained across these parasite\'s speciation, named collectively as the trypanosomatid ancestral supernumerary chromosome (TASC). TASC has most genes in the same coding strand, is expressed as a disomic chromosome (even having four copies), and has increased potential for functional variation, but it purges highly deleterious mutations more efficiently than other chromosomes. The evidence of stringent control over gene expression in this chromosome suggests that these parasites have adapted to mitigate the fitness cost associated with this ancient chromosomal duplication.

We report the complete telomere-to-telomere genome assembly of Oldenlandia diffusa which renowned in traditional Chinese medicine, comprising 16 chromosomes and spanning 499.7 Mb. The assembly showcases 28 telomeres and minimal gaps, with a total of only five. Repeat sequences constitute 46.41% of the genome, and 49,701 potential protein-coding genes have been predicted. Compared with O. corymbosa, O. diffusa exhibits chromosome duplication and fusion events, diverging 20.34 million years ago. Additionally, a total of 11 clusters of terpene synthase have been identified. The comprehensive genome sequence, gene catalog, and terpene synthase clusters of O. diffusa detailed in this study will significantly contribute to advancing research in this species\' genetic, genomic, and pharmacological aspects.

We summarize the copy number variations (CNVs) and phenotype spectrum of infantile epileptic spasms syndrome (IESS) in a Chinese cohort. The CNVs were identified by genomic copy number variation sequencing. The CNVs and clinical data were analyzed. 74 IESS children with CNVs were enrolled. 35 kinds of CNVs were identified. There were 11 deletions and 5 duplications not reported previously in IESS, including 2 CNVs not reported in epilepsy. 87.8% were de novo, 9.5% were inherited from mother and 2.7% from father. Mosaicism occurred in one patient with Xq21.31q25 duplication. 16.2% (12/74) were 1p36 deletion, and 20.3% (15/74) were 15q11-q13 duplication. The age of seizure onset ranged from 17 days to 24 months. Seizure types included epileptic spasms, focal seizures, tonic seizures, and myoclonic seizures. All patients displayed developmental delay. Additional features included craniofacial anomaly, microcephaly, congenital heart defects, and hemangioma. 29.7% of patients were seizure-free for more than 12 months, and 70.3% still had seizures after trying 2 or more anti-seizure medications. In conclusion, CNVs is a prominent etiology of IESS. 1p36 deletion and 15q duplication occurred most frequently. CNV detection should be performed in patients with IESS of unknown causes, especially in children with craniofacial anomalies and microcephaly.