We present a series of microdeletion and microduplication syndromes (MMSs) observed in our clinical practice over a three-year period from 2020 to 2023. Microdeletion and microduplication syndromes, characterized by chromosomal deletions or duplications of less than five megabases, pose challenges in terms of diagnosis, especially prenatal and clinical management. Clinically, MMSs encompass a broad spectrum of manifestations, ranging from intellectual disability and developmental delays to congenital anomalies, facial dysmorphisms, and neurobehavioral abnormalities. Notable examples include well-characterized syndromes such as DiGeorge syndrome (22q11.2 deletion), Prader–Willi syndrome (15q11–q13 deletion), and Williams syndrome (7q11 deletion). Our study focuses on the genetic foundations and prenatal ultrasound findings of these syndromes, with an emphasis on cases associated with intellectual disability. Using SNP array technology, we delve into the evolving landscape of diagnostic methods, providing a nuanced understanding of copy number variations (CNVs) and their implications. Prenatal diagnosis allows for the early detection of MMSs, enabling parents and healthcare providers to make informed decisions about the pregnancy and plan for appropriate medical care and interventions. Beyond theoretical considerations, our article bridges the gap between research and practical application by offering insights derived from clinical cases. Through the presentation of specific cases, we aim to contribute valuable data to the broader discourse on MMSs, fostering knowledge exchange and enhancing the medical community’s awareness of these complex genetic conditions.

Objectives: This study aimed to characterize the types and frequencies of sex chromosome aneuploidies (SCAs) detected through invasive prenatal testing, evaluate the concordance between non-invasive prenatal testing (NIPT) and confirmatory diagnostic methods, and assess the challenges faced during genetic counseling following SCA diagnosis. Study Design: A retrospective review was conducted on 842 prenatal samples collected between 2020 and 2024 in a tertiary private medical center. Samples included amniotic fluid, chorionic villi, and products of conception. Testing involved rapid QF-PCR for aneuploidy detection, followed by SNP-based chromosomal microarray analysis (CMA). NIPT results with high risk for sex chromosomes aneuploidies were correlated with invasive testing outcomes in 19 cases. Results: Sex chromosome aneuploidies were identified in 67 cases (7.96%), with Turner syndrome (45, X) being the most frequent (23 cases, including six mosaics), followed by Klinefelter syndrome (18 cases), 47, XYY (14 cases), and trisomy X (12 cases). Among 19 NIPT-tested cases, 10 were true positives, 5 false positives, and 4 false negatives, including two mosaic Turner syndrome cases undetected by NIPT. Discordances were attributed to factors such as mosaicism and placental anomalies. Conclusions: Prenatal diagnosis of SCAs via invasive testing remains crucial due to NIPT’s limited sensitivity for mosaicism and false positives. Comprehensive genetic counseling is essential to navigate diagnostic uncertainties and optimize prenatal management and postnatal outcomes.

Background: Tessadori–Bicknell–van Haaften syndrome (OMIM #619759) is a rare autosomal dominant neurodevelopmental disorder associated with heterozygous variants in genes encoding histone H4 proteins. The condition is characterized by global developmental delay, craniofacial dysmorphism, hypotrophy, intellectual disability, and ophthalmologic anomalies. More than 30 individuals with variants in histone H4 genes have been reported to date, reflecting the genetic heterogeneity of this emerging disorder. According to OMIM, the association between the H4C11 gene and Tessadori–Bicknell–van Haaften syndrome 2 is currently considered provisional. Methods: We report the case of a 5-year-old female presenting with expressive language delay, social interaction difficulties, and craniofacial features including microcephaly, exophthalmos, and periorbital fullness (“puffy eyes”). Family history revealed two sisters with borderline intellectual functioning who have not undergone genetic testing. The patient’s father carried the same heterozygous H4C11 variant (c.97C > T), while maternal testing was negative. Results: Neuropsychological evaluation revealed borderline intellectual functioning (IQ 73 at first assessment, 85 at follow-up) with persistent expressive language impairment. Ophthalmologic examination confirmed congenital exophthalmos and hypermetropic astigmatism. Laboratory investigations showed low ferritin and mildly elevated TSH levels, which may have contributed to the observed growth delay. At follow-up, the patient showed an increase in IQ score (73 to 85); however, test–retest variability cannot be excluded. Conclusions: This case highlights the importance of careful clinical assessment and cautious interpretation of genetic findings in children with neurodevelopmental delay. Familial segregation of a variant of uncertain significance (VUS), in the absence of functional evidence, should be interpreted conservatively and integrated with detailed phenotypic evaluation to guide clinical management and follow-up.