Search Results (74)

Background/Objectives: 22q11.2 microduplication syndrome is a rare genetic disorder characterized by the presence of one or two additional copies of a segment within the 22q11.2 region of chromosome 22. While much of the literature has focused on the deletion variant leading to DiGeorge syndrome, the duplication counterpart has gained increasing attention due to its clinical variability and under-recognition. This review aims to deliver new possibilities to genetic counseling that can be provided in prenatal and postnatal cases as the phenotype of 22q11.2 microduplication carriers cannot be fully predicted. Methods: In the present study, a total of 12 (5 prenatal and 7 postnatal) cases were diagnosed through array-CGH and combined with 679 (95 prenatal and 584 postnatal) cases reported in the literature. This review summarizes the published evidence available up to April 2025. Data on clinical presentations, genetic findings, diagnostic methodologies, and outcomes were extracted and analyzed. Results: The combination of our cases and the reported cases with 22q11.2 microduplication syndrome revealed a broad phenotypic spectrum. Common clinical features include neurodevelopmental disorders, and cardiac anomalies. Importantly, the syndrome exhibits variable expressivity and reduced penetrance, with more than 70% of the findings to be inherited by one of the parents. Conclusions: 22q11.2 microduplication syndrome presents a heterogeneous clinical picture with variable expressivity and incomplete penetrance, posing challenges in diagnosis and genetic counseling, particularly when predicting prenatal outcomes. Awareness of its diverse manifestations is crucial for clinicians to consider this syndrome in the differential diagnosis and to provide informed counseling. Full article

Background: Monochorionic twin pregnancies provide a unique model to investigate fetal phenotypic discordance, because both fetuses share a single placenta and interconnected vascular circulation. Although most monochorionic twins are monozygotic, clinically relevant differences may arise through genetic, epigenetic, placental, and stochastic developmental mechanisms. Methods: This systematic review was conducted according to PRISMA 2020 and registered in PROSPERO (CRD420261432361). PubMed/MEDLINE, Embase, and Scopus were searched from inception to June 2026. Eligible studies included monochorionic monozygotic twin pairs with discordant congenital, developmental, or syndromic phenotypes, confirmed or clearly inferable monochorionicity, and at least one genomic, cytogenetic, or epigenetic investigation; studies describing confirmed monochorionic dizygotic twinning were excluded. Findings were synthesized qualitatively. Results: The search identified 1357 records. After duplicate removal and screening, 48 studies fulfilled the eligibility criteria, comprising 441 monozygotic twin pairs; 37 were single-pair case reports, whereas one large retrospective cohort study alone contributed 193 pairs (44% of the entire pooled sample). Reported phenotypes included congenital heart disease, chromosomal abnormalities, disorders of sex development, imprinting disorders, neurodevelopmental disease, endocrine disorders, renal anomalies, skeletal disorders, and multisystem malformations. Molecular methods included karyotyping, FISH, chromosomal microarray, array-CGH, CNV analysis, WES, WGS, targeted sequencing, and methylation profiling. Proposed mechanisms included postzygotic chromosomal errors, somatic mutations, tissue-specific mosaicism, discordant or shared CNVs, differential methylation, imprinting defects, variable expressivity, blood chimerism, unequal placental sharing, TTTS, TAPS, sFGR, and uteroplacental insufficiency. Conclusions: Phenotypic discordance in monochorionic twins is rarely explained by a single mechanism. Available evidence supports a multifactorial model in which postzygotic genetic events, epigenetic regulation, placental vascular factors, and stochastic developmental processes interact. Full article

49,XXXXY syndrome (Fraccaro syndrome) is a rare sex chromosome pentasomy, historically considered a severe variant within the Klinefelter spectrum. It is characterized by intellectual disability, craniofacial dysmorphism, skeletal anomalies, hypogonadism, and congenital cardiac defects. Although neuroimaging abnormalities have increasingly been recognized in 49,XXXXY syndrome, neonatal diagnosis prompted primarily by ventriculomegaly remains rare. We report a neonate with prenatally detected ventriculomegaly in whom postnatal evaluation revealed cleft palate, congenital cardiac defects, bilateral cryptorchidism, and auditory dysfunction. Cranial ultrasonography and brain magnetic resonance imaging demonstrated bilateral ventriculomegaly with colpocephaly and a cavum vergae variant. Cytogenetic analysis confirmed the presence of a 49,XXXXY karyotype. This case highlights ventriculomegaly as a potential early diagnostic clue in 49,XXXXY syndrome and underscores the importance of chromosomal analysis in neonates presenting with structural brain abnormalities associated with multisystem anomalies. Early recognition is important for timely multidisciplinary surveillance and long-term endocrine follow-up. Full article

(1) Background: Integrated bioarchaeological approaches combining osteological and ancient DNA analyses provide powerful insights into health, disease, and population history in past societies. However, the relationship between rare skeletal variations, genetic disorders, and ancestry remains insufficiently explored within single individuals. This study aimed to investigate the combined osteological, paleopathological, and genetic characteristics of a Roman-period individual from southwestern Anatolia. (2) Methods: A multidisciplinary approach was applied to the skeletal remains of an adult male recovered from the Sekköy excavation site. Osteological analysis was conducted to assess cranial morphology, pathological lesions, and dental status. Ancient DNA was extracted from petrous bone under strict contamination control. The hemoglobin beta (HBB) gene was analyzed using Next Generation Sequencing and validated by Sanger sequencing. Y-chromosomal STR analysis was performed to determine paternal lineage. (3) Results: Osteological examination revealed a rare craniovertebral anomaly consistent with a third occipital condyle, along with porotic hyperostosis and extensive antemortem dental pathology, indicating prolonged physiological stress. Genetic analysis identified a heterozygous hemoglobin S mutation (HbAS; rs334), confirmed by both next-generation sequencing and Sanger sequencing, providing direct molecular evidence of hereditary hemoglobinopathy. Y-STR profiling assigned the individual to haplogroup R1b (predicted based on Y-STR data), indicating affiliation with Western Eurasian paternal lineages. (4) Conclusions: Despite the presence of comparable skeletal stress indicators, the integration of osteological and genetic data revealed a complex interaction between anatomical variation, chronic physiological stress, and inherited disease. The co-occurrence of a rare cranial anomaly, HbS mutation, and a defined paternal lineage represents a unique bioarchaeological case. These findings highlight the value of integrating skeletal and molecular approaches to reconstruct individual health profiles in archaeological contexts and demonstrate the methodological potential of interdisciplinary bioarcheological analysis. Full article

Background: Beckwith–Wiedemann syndrome (BWS) is a rare congenital overgrowth disorder caused by genetic and epigenetic alterations on chromosome 11p15.5. While macroglossia, abdominal wall defects, and tumor predisposition are well recognized, hearing impairment has been sporadically reported. Objectives: The aim of this study is to review audiological features, surgical management, and rehabilitation in BWS, and we additionally present three cases with comprehensive longitudinal audiological follow-up. Methods: A systematic review of PubMed and Scopus was conducted according to PRISMA guidelines, including studies reporting audiological findings in patients with confirmed BWS. Studies without audiological data or reporting only normal-hearing patients were excluded. Data on hearing loss type, severity, genetics, clinical features, imaging, surgical interventions, and outcomes were extracted. A narrative synthesis was conducted; no meta-analysis was performed due to the heterogeneity and limited number of available studies. Data extraction was performed independently by two reviewers who independently screened titles, abstracts, and full texts, with disagreements resolved by discussion. In addition, three original case reports from our institution were included to further illustrate the clinical and rehabilitative variability of hearing impairment in BWS. Results: We identified 40 patients from the review, but only 12 of them reported audiological data (e.g., hearing thresholds, type of hearing loss, or diagnostic tests). Ossicular chain anomalies, particularly stapes fixation, were frequently observed. Surgical management improved hearing in selected cases, while bone conduction devices (BCD) or conventional amplification were effective alternatives when surgery was contraindicated. Genetic analyses revealed CDKN1C mutations or imprinting defects in nine patients. Conclusions: Hearing impairment in BWS is clinically relevant and often conductive, likely related to middle-ear anomalies. Early, multidisciplinary audiological evaluation—including imaging when indicated—and individualized rehabilitation can optimize auditory and communicative outcomes. The evidence is limited by the small number of studies and heterogeneous reporting of audiological outcomes. Full article

Background/Objectives: Umbilical–portal–systemic venous shunts (UPSVS) are rare fetal vascular anomalies with heterogeneous embryologic origins and variable perinatal implications. Although prenatal diagnosis has increased with advances in fetal imaging, data correlating prenatal subclassification with structural/genetic abnormalities and neonatal outcomes remain limited. Methods: This retrospective study included 50 fetuses prenatally diagnosed with UPSVS at a tertiary referral perinatology center between 2021 and 2025. Cases were subclassified according to the Achiron prenatal classification into Type 1 umbilical–systemic shunt (USS), Type 2 ductus venosus–systemic shunt (DVSS), Type 3a intrahepatic portosystemic shunt (IHPSS), and Type 3b extrahepatic portosystemic shunt (EHPSS). Prenatal ultrasound, Doppler, fetal echocardiography, and genetic testing (karyotype and chromosomal microarray) were analyzed. Perinatal metrics—including structural/genetic anomalies, fetal growth restriction (FGR), termination of pregnancy (TOP), and neonatal outcomes—were evaluated with postnatal verification. Results: The distribution of subtypes was Type 1: 28% (14/50), Type 2: 48% (24/50), Type 3a: 20% (10/50), and Type 3b: 4% (2/50). Gestational age at diagnosis was significantly higher in Type 3a compared with Type 1 and Type 2 (32.2 ± 2.4 vs. 21.1 ± 6.7 and 22.4 ± 5.8 weeks; p < 0.001). Structural anomalies were most frequent in Type 1 (13/14, 92.9%; p < 0.001), while FGR predominated in Type 3a (9/10, 90%; p = 0.006). Ductus venosus (DV) agenesis was universal in Type 1 (14/14) and Type 3b (2/2), absent in Type 2 (0/24), and present in 20% of Type 3a (2/10) (p < 0.001). Genetic abnormalities were detected in 57% of Type 1 (4/7) and 56% of Type 2 (9/16) fetuses, with trisomy 21 most prevalent in Type 2. TOP was highest in Type 1 (8/14, 57.1%; p < 0.001). Adverse neonatal outcomes occurred primarily in Type 1 and Type 3b (p < 0.001), whereas Type 2 demonstrated favorable neonatal outcomes. Conclusions: UPSVS subtype is strongly associated with structural/genetic anomalies, FGR, and neonatal outcomes, underscoring the importance of prenatal subclassification in prognostic assessment and counseling. Type 1 and Type 3b represent the highest—risk subgroups requiring delivery planning in tertiary centers, while Type 2 generally exhibits a benign perinatal course. The association between Type 3a and FGR highlights the need for detailed evaluation of the hepatic venous system in growth-restricted fetuses. However, interpretation of subgroup-specific associations should consider the relatively small sample size of Type 3b cases and the limited genetic testing performed in some Type 3a fetuses. Multicenter prospective studies are warranted to standardize diagnostic algorithms, optimize genetic testing strategies, and refine perinatal management. Full article

Background: Increased nuchal translucency (NT) is associated with an elevated risk of genetic abnormalities and structural malformations. The clinical utility of invasive testing and the optimal diagnostic approach in mildly increased NT (3.0–3.4 mm) is debated. This study aimed to evaluate genetic and ultrasound findings in this subgroup and to assess the diagnostic yield of advanced genetic testing. Methods: We retrospectively included a total of 107 fetuses with NT between 3.0 and 3.4 mm from a single fetal medicine unit. Complete outcome data were available for 97 pregnancies. Invasive prenatal testing with standard karyotype, chromosomal microarray analysis (CMA) and RASopathy panel testing were offered. All patients underwent detailed ultrasound examination to detect structural abnormalities at 16 and 20 weeks, regardless of whether invasive testing was performed. Results: Invasive prenatal testing, amniocentesis or chorionic villus sampling, (CVS), was performed in 77/97 cases (79.4%). Genetic abnormalities were detected in 28/97 (28.9%). Overall, five rare genetic anomalies were identified; none would have been detected by quantitative fluorescent polymerase chain reaction (QF-PCR) or non-invasive prenatal testing (NIPT). Two anomalies were detectable by standard karyotype, two exclusively by CMA and one exclusively by RASopathy panel. When considering all cases undergoing advanced genetic testing (CMA or RASopathy panel, n = 35) the overall diagnostic yield was 8.5% (3/35). When calculated across the entire cohort with complete follow-up, the additional diagnostic yield was 3.1% (3/97). Major structural malformations were identified in 17/97 cases (17.5%), of which 10 (58.8%) were associated with genetic abnormalities. Conclusions: Fetuses with NT measurements between 3.0 and 3.4 mm show a substantially increased risk of genetic abnormalities and structural malformations. These findings support a comprehensive prenatal evaluation, including invasive testing with advanced genetic analysis and detailed ultrasound assessment, to optimize diagnosis and counseling. Full article

Peters-Plus syndrome is a rare autosomal recessive disorder caused by biallelic pathogenic variants in the B3GLCT gene and characterized by multisystem involvement. Fewer than 100 cases have been reported to date, and only a limited number have been diagnosed prenatally. Prenatal identification is challenging due to the variable and non-specific nature of fetal findings and the frequent absence of detectable ocular anomalies during routine ultrasound. We report a prenatal diagnosis of Peters-Plus syndrome in a monochorionic diamniotic twin pregnancy, based on the progressive identification of early-onset intrauterine growth restriction, rhizomelic limb shortening, craniofacial dysmorphism, and mild central nervous system abnormalities. Standard cytogenetic and chromosomal microarray analyses were normal, prompting extended genetic testing. Prenatal exome sequencing identified a homozygous pathogenic splice-site variant (c.660+1G>A) in B3GLCT in both fetuses, confirming the diagnosis. This case highlights the importance of recognizing suggestive multisystem prenatal findings and the crucial role of advanced genetic testing in achieving an accurate prenatal diagnosis. Early molecular confirmation enables appropriate parental counseling regarding prognosis, recurrence risk, and future reproductive options. Full article

Background/Objectives: Systemic sclerosis (SSc) is a rare, complex autoimmune disease characterized by fibrosis of the skin and internal organs. While its pathogenesis is not fully understood, chromosomal instability and telomere attrition have emerged as significant areas of investigation. Methods: This review provides a historical narrative perspective and synthesizes current findings on the role of these genomic anomalies in SSc pathogenesis. We synthesized findings from foundational and recent research articles investigating genotoxic factors, chromosomal aberrations, and telomere biology in SSc. Results: There is a strong historical basis for chromosomal instability in SSc, manifesting as micronuclei, translocations, and breaks. This instability is driven by clastogenic factors and oxidative stress. SSc-specific autoantibodies are implicated; anti-centromere antibodies correlate with aneuploidy and micronuclei, while anti-topoisomerase I may inhibit DNA repair. SSc is also characterized by significant telomere attrition, first reported in 1996 and now confirmed by additional genetic studies. This telomere loss is associated with reduced telomerase activity and the presence of autoantibodies against telomere-associated proteins, including shelterin components. Conclusions: We conclude that inflammation, telomere attrition, and chromosomal instability are linked in a self-perpetuating cycle that drives SSc pathogenesis. We propose that an initial inflammatory stimulus leads to reactive oxygen species production, causing telomere damage and attrition. Critically short telomeres trigger faulty DNA repair mechanisms, such as breakage–fusion–bridge cycles, resulting in chromosomal instability. This genomic damage, in turn, acts as a danger signal, further activating inflammatory pathways and creating a feedback loop that perpetuates fibrosis. Full article

Chromosome 6q deletion syndrome is a rare entity that has a highly variable clinical presentation and size of deletions. The most frequent manifestations of 6q terminal deletion are intellectual disability, facial dysmorphism, brain structural anomalies, and congenital heart defects. The phenotype is not clinically recognizable, except in those who harbor a terminal 6q deletion that includes the ARID1B gene, in whom features similar to Coffin–Siris syndrome (CSS) can be observed. We report the case of a female newborn with a prenatal diagnosis of a terminal deletion on 6q25.1q27, which encompasses the ARID1B gene, and who was diagnosed with CSS during the neonatal period. From our review, we found that facial gestalt, hypertrichosis, and fifth fingernail aplasia/hypoplasia, along with other features, such as vertebral defects and cystic hygroma (or webbed neck), correlated with the presence of a CSS causally related to 6q25.3 small deletions that include the ARID1B gene. Full article

Background: Non-invasive prenatal testing (NIPT) based on cell-free fetal DNA (cfDNA) in maternal blood has revolutionized prenatal screening for trisomies 21, 18, and 13. This approach, based on next-generation sequencing (NGS), usually allows the detection of other chromosomal abnormalities; however, their clinical value in routine practice requires further evidence. Objectives: This study aimed to assess the experience and clinical utility of genome-wide NIPT in pregnant women at intermediate risk in the autonomous communities of Aragón and Valencia, Spain. Methods: For this purpose, a retrospective cohort study was conducted between 2020 and 2024 across two public hospitals. Pregnant women at intermediate risk for trisomies 21, 18, or 13, were included, as well as those meeting specific clinical criteria. Participants were offered either basic or expanded NIPT, and positive results were confirmed by invasive prenatal testing or placental analysis. Results: Among 9,059 expanded NIPT tests, 132 (1.45%) indicated a high-risk result for less common chromosomal anomalies, comprising 60 rare autosomal aneuploidies (RAAs), 39 copy number variants (CNVs), 23 sex chromosome aneuploidies (SCAs), and 10 multiple abnormalities. The positive predictive value (PPV) was 5.5% for RAAs in the fetus, 12.8% for CNVs (31% for deletions), and 58% for SCAs. Conclusions: Several confirmed anomalies were clinically significant and would not have been detected through conventional screening. Opportunistic use of expanded NIPT enables the detection of additional clinically relevant abnormalities, potentially improving obstetric management without substantially increasing invasive testing. Full article

Copy number variations (CNVs) affecting the chromosomal region 21q21.3–q22.13 are rare and have been increasingly associated with neurodevelopmental abnormalities and multisystemic manifestations. In this study, we aimed to characterize the clinical, genomic, and genotype–phenotype correlations of a Moroccan child carrying a de novo microdeletion in this region. Whole exome sequencing (WES) was performed using sequencing-by-synthesis technology on the GenoLab M platform, and CNV detection was achieved through the SeqOne platform. Variant interpretation was conducted using the Integrative Genomics Viewer (IGV), and a custom gene–phenotype heatmap was generated in R (ComplexHeatmap and pheatmap) based on OMIM, ClinVar, and DECIPHER databases to prioritize candidate genes within the deleted segment. The patient presented with global developmental delay, microcephaly, psychomotor and staturo-ponderal retardation, facial dysmorphism, epilepsy responsive to treatment, and cerebral anomalies, including passive biventricular hydrocephalus and diffuse cortical atrophy. WES-CNV analysis identified a heterozygous de novo microdeletion of approximately 8.2 Mb in 21q21.3–q22.13, encompassing 124 clinically relevant genes. Integrated analysis confirmed the pathogenicity of the deletion and highlighted genotype–phenotype correlations, particularly implicating dosage-sensitive genes such as SON and RUNX1. This case underlines the clinical utility of combining WES, CNV analysis, and phenotype-based bioinformatic tools for diagnosing complex microdeletion syndromes, contributes to understanding genotype–phenotype relationships in 21q21.3–q22.13 deletions, and supports improved clinical interpretation and patient management. Full article

Background and Clinical Significance: Wolf–Hirschhorn syndrome (WHS, OMIM #194190) is caused by deletion of the distal short arm of chromosome 4. It is characterized by intrauterine growth restriction (IUGR), developmental delay, epilepsy, distinctive facial features, and urinary tract anomalies, particularly renal hypoplasia. However, the histological profile of renal involvement in WHS is rarely documented. Case presentation: We report a case of fetal WHS with renal hypoplasia and histological evidence of oligomeganephronia (OMN). At 21 weeks’ gestation, a prenatal ultrasound revealed oligo/anhydramnios and IUGR. Genetic testing (karyotype and CGH-array) confirmed a de novo 17.92 Mb terminal deletion from 4p16.3 to 4p15.31. The pregnancy was legally terminated at 23 weeks. The autopsy showed characteristic WHS dysmorphisms, growth restriction, and markedly small kidneys. Histology revealed OMN with a thinned renal cortex with reduced glomeruli, mainly hypoplastic, some of which were hypertrophic, and dilated proximal tubules. Scattered medullary tubules were present within the tubulointerstitial compartment, alongside thickened tubular basement membranes highlighted by Collagen IV staining. Conclusions: This case suggests that OMN may be a histological hallmark of renal hypoplasia in WHS, especially in larger 4p deletions. Recognizing this pattern may help with prenatal prognosis and clinical management. Further studies are needed to confirm this association. Full article

The expanded newborn screening (NBS) program in the Russian Federation, launched in 2023, includes the detection of severe forms of T- and B-cell immunodeficiencies via TREC/KREC quantification. We report a rare case of a male infant having multiple congenital anomalies and lymphopenia identified through this program. Genetic testing revealed a 25.8 Mb terminal deletion spanning 13q31.2–qter, consistent with 13q deletion syndrome. Initial NBS revealed reduced TREC levels, prompting further evaluation. The patient exhibited a complex phenotype, including central nervous system malformation (alobar holoprosencephaly), severe congenital heart disease, renal hypoplasia, limb and genitourinary anomalies, and facial dysmorphism. Postnatal complications included pneumonia, pleuritis, and chylothorax. Flow cytometry demonstrated mild T- and B-cell lymphopenia. The genomic defect was characterized using long-read third-generation sequencing, enabling precise breakpoint identification and accurate mapping of deleted genes. The deletion was confirmed via subtelomeric FISH analysis. The patient died at 7 months of age due to the progression of underlying congenital anomalies and associated complications. Our findings broaden the clinical characterization of distal 13q deletion syndrome and demonstrate the value of long-read sequencing in structural chromosomal analysis. They further highlight the difficulties of caring for neonates having complex malformations and immune dysfunction. Given the potential for both primary and secondary immune disturbances, comprehensive immunological evaluation should be considered in patients having 13q deletion syndrome to improve diagnostic accuracy and inform appropriate clinical management. Full article

Background and Clinical Significance: Binder syndrome or maxillonasal dysplasia is a rare developmental disorder affecting the anterior maxilla and nasal complex, characterized by midfacial hypoplasia, a flattened nasal bridge, and increased nasofrontal angle. Case Presentation: We present a case series of seven fetuses diagnosed with Binder phenotype through targeted ultrasound examination at our prenatal diagnosis center during the SARS-CoV-2 pandemic, between September 2021 and July 2023, including the first case described in the literature before 14 weeks. The median gestational age at diagnosis was 21 weeks. Ultrasound features included flattened fetal facial profile, increased nasofrontal angle (>143°), verticalized nasal bones and widened maxillary alveolar arch. Five cases presented as isolated anomalies, while two showed associated findings including growth restriction and polyhydramnios. Invasive prenatal diagnosis was offered in all cases, with three patients consenting to amniocentesis, all revealing normal karyotype and chromosomal microarray. Pregnancy outcomes varied: three patients opted for termination of pregnancy, one case resulted in intrauterine fetal demise, one delivered prematurely with confirmed postnatal phenotype, and two continued pregnancy with normal delivery. Conclusions: This relatively high case frequency within a short timeframe suggests that Binder syndrome, while rare, may not be as uncommon as previously reported. Accurate ultrasound diagnosis combined with comprehensive genetic counseling enables appropriate pregnancy management and optimal perinatal outcomes. Full article