OBJECTIVE: To explore the application value of artificial intelligence (AI)-assisted chromosomal karyotype analysis in the diagnosis of prenatal chromosomal mosaicism. METHODS: A retrospective analysis was conducted on 172 pregnant women who underwent amniocentesis at the Department of Medical Genetics and Prenatal Diagnosis, the Third Affiliated Hospital of Zhengzhou University between January 2019 and December 2024. All cases whose fetuses were diagnosed with chromosomal mosaicism via karyotype analysis and stratified into two groups based on the analytical software employed: the conventional analysis group (n = 70), which utilized Leica analysis software for karyotype image recognition and cell counting; and the AI-assisted analysis group (n = 102), which utilized AI-assisted software for the same procedures. The clinical performance of AI-assisted karyotype analysis in diagnosing chromosomal mosaicism was comprehensively evaluated by comparing the types of mosaic karyotypes, distribution of mosaic ratios, and verification outcomes of different detection modalities between the two groups. This study was approved by the Medical Ethics Committee of the Third Affiliated Hospital of Zhengzhou University (Ethics No.: 2024-406-01). RESULTS: No statistically significant difference was observed in baseline characteristics (maternal age, gestational week, and indications for prenatal diagnosis) between the two groups. Regarding the detection efficacy for numerical and structural mosaicisms, no significant difference was found in the detection of numerical mosaicism. However, the conventional analysis group exhibited a significantly higher detection rate of autosomal structural mosaicism compared to the AI-assisted group (11.43% vs. 0.98%, P < 0.05). Numerical mosaicism cases were further verified using copy number variation sequencing (CNV-seq) and/or fluorescence in situ hybridization (FISH). The AI-assisted group demonstrated a significantly lower inconsistency rate (5.56% vs. 20.41%, P < 0.05) compared to the conventional group. For low-proportion (< 10%) chromosomal mosaicism, the AI-assisted group had a significantly lower detection rate (13.25% vs. 29.69%, P < 0.05). Subsequent validation of low-proportion mosaicism by CNV-seq and/or FISH showed a higher consistency rate in the AI-assisted group (81.82% vs. 54.55%), though the difference did not reach statistical significance (P = 0.360). CONCLUSION For the karyotyping analysis of prenatal chromosomal mosaicism, AI-assisted karyotype analysis shows high accuracy and consistency in identifying numerical chromosomal mosaicism, particularly in reducing the detection of low-proportion (< 10%) mosaicism while improving verification accuracy. AI-assisted analysis can significantly improve the detection accuracy of numerical mosaicism and mitigate the risk of misclassification for low-proportion (< 10%) mosaicism, thereby providing more precise clinical evidence for the prenatal diagnosis of chromosomal mosaicisms.
Humans ; Female ; Mosaicism ; Pregnancy ; Karyotyping/methods* ; Artificial Intelligence ; Prenatal Diagnosis/methods* ; Adult ; Retrospective Studies ; Chromosome Disorders/genetics* ; Amniocentesis

OBJECTIVE: To investigate the detection patterns, clinical phenotypic characteristics, and differences in diagnostic timeliness of Klinefelter syndrome (KS) across prenatal and postnatal stages, with an aim to provide a basis for optimizing strategies for early screening, diagnosis, and intervention. METHODS: A retrospective study was conducted to analyze data from two phases. The prenatal diagnosis group included 33,302 pregnant women who underwent amniocytic karyotyping due to advanced maternal age, abnormal ultrasound findings, or high-risk non-invasive prenatal testing (NIPT). The postnatal diagnosis group included 52,101 patients who underwent peripheral blood karyotyping due to primary infertility, abnormal external genitalia, or growth and developmental abnormalities. Additionally, medical histories of adult diagnosed patients were reviewed retrospectively to identify early occult symptoms. This study was approved by the Medical Ethics Committee of Chengdu Women's and Children's Central Hospital (Ethics No.: LCYJ-2025-030). RESULTS: In the prenatal group, 96 cases of KS were detected (detection rate 0.29%). The primary indications for referral were NIPT indicating sex chromosome abnormalities (45.83%), advanced maternal age (16.66%), and ultrasound abnormalities (17.70%). In the postnatal group, 128 cases of KS were detected (detection rate 0.25%). Clinical presentations were primarily primary infertility/azoospermia (77.34%), and the patients were predominantly adults (84.40%). Retrospective analysis revealed that adult patients presented with specific physical signs that had been overlooked during childhood. CONCLUSION As KS lacks typical early clinical manifestations, diagnosis is often delayed until adulthood when reproductive needs arise, showing a pattern of "passive detection" and resulting in missed opportunities for optimal intervention. By conducting a comparative analysis of prenatal diagnostic data and postnatal retrospective data, a risk association model linking prenatal screening indications with childhood-specific signs was developed. This study has provided empirical evidence for establishing a multidisciplinary, full life-cycle management system of "screening ~ diagnosis ~ monitoring ~ intervention" helping to shift from "passive detection in adulthood" to "proactive management across the entire life course," and laid a foundation for improving early diagnosis rate and long-term quality of life for patients.
Humans ; Klinefelter Syndrome/genetics* ; Female ; Adult ; Pregnancy ; Retrospective Studies ; Prenatal Diagnosis/methods* ; Male ; Phenotype ; Karyotyping ; Young Adult ; Adolescent ; Middle Aged

OBJECTIVE: To summarize the clinical and genetic characteristics of children with Silver-Russell syndrome (SRS) and improve the recognition of this disease. METHODS: A retrospective analysis was conducted on the clinical manifestations and genetic testing results of 29 children with SRS diagnosed at the Children's Hospital Affiliated to Zhengzhou University between March 2016 and June 2025. RESULTS: The 29 children had included 18 boys and 11 girls, with the age ranging from 2 months to 16 years. Their primary clinical manifestations included postnatal growth retardation (100%), small for gestational age (SGA) (100%), characteristic facial features (90%), limb asymmetry (83%), feeding difficulties (76%), ulnar deviation of the fifth finger (69%), body mass index (BMI) of < -2 SD (62%), and abnormal bone age (55%), including 15 cases with delayed bone age for an average of 1.5 years and 1 case with advanced bone age for 2.5 years. Additional manifestations included abnormal sexual development in 11 cases (38%), dental malocclusion in 11 cases (38%), allergic diseases in 10 cases (34%), cardiac diseases in 9 cases (31%), skeletal abnormalities in 7 cases (24%), renal hypoplasia in 5 cases (17%), and abnormal cranial MRI findings in 5 cases (17%). Twenty children were treated with recombinant human growth hormone (rhGH) at a dose of 0.1 ~ 0.15 U/(kg.d). Among them, 7 cases achieved annual height increase of ≥ 10 cm, 11 cases achieved annual height increase of ≥ 5 ~ 9 cm, and 2 cases achieved annual height increase < 5 cm. Twenty three children exhibited hypomethylation of imprinted genes in the chromosome region of 11p15, 4 presented maternal uniparental disomy of chromosome 7 [UPD(7)mat], and 2 had harbored nonsense variants of the HMGA2 gene. CONCLUSION SRS patients may present with diverse clinical manifestations including postnatal growth retardation, SGA, characteristic facial features, limb asymmetry, feeding difficulties, and ulnar deviation of the fifth finger. Most patients may exhibit abnormal methylation in the 11p15 region. rhGH therapy can improve the height of these patients.
Humans ; Silver-Russell Syndrome/diagnosis* ; Male ; Female ; Child ; Child, Preschool ; Infant ; Adolescent ; Retrospective Studies

Introduction: Swyer syndrome (46, XY gonadal dysgenesis) is a rare disorder of sex development, characterized by a phenotypic female with streak gonads and hypergonadotropic hypogonadism. It presents with primary amenorrhea and delayed puberty. Overlapping clinical features with Turner syndrome may cause diagnostic uncertainty, highlighting the role of karyotypic evaluation in diagnosis. Case: A 35-year-old phenotypic female was first evaluated at age 27 during admission for an acute viral illness, when incidental findings of primary amenorrhea, short stature (height 131 cm), webbed neck, pectus excavatum, and absent secondary sexual characteristics raised suspicion of Turner syndrome. She had hypertension, with initial imaging suggesting coarctation of the thoracic aorta. CT angiography showed focal narrowing of the descending aorta; multidisciplinary review favored aortic folding, and she was managed conservatively. Endocrine evaluation demonstrated hypergonadotropic hypogonadism, with markedly elevated follicle-stimulating hormone (FSH 108.6 IU/L) and luteinizing hormone (LH 23.16 IU/L) in the presence of low estradiol levels. Pelvic imaging revealed an atrophic uterus with absence of bilateral ovaries, consistent with gonadal dysgenesis. Karyotypic analysis was performed, demonstrating a 46, XY genotype with confirmed SRY gene presence, establishing the diagnosis of Swyer syndrome. DEXA scan demonstrated osteoporosis, in keeping with prolonged hypogonadism. She was commenced on hormone replacement therapy, resulting in the development of secondary sexual characteristics and regular withdrawal bleeding. She remains under structured multidisciplinary follow-up, with endocrine-led management of hypothyroidism and osteoporosis, alongside cardiology follow-up and gynecological surveillance. Conclusion This case highlights the diagnostic complexity of disorders of sex development with overlapping phenotypes and the need for re-evaluation when clinical progression is atypical. Diagnosis enables hormone replacement therapy for induction of secondary sexual characteristics and preservation of bone health. Integration of clinical, biochemical, and genetic data within a multidisciplinary framework is essential to achieve diagnostic accuracy and optimize outcomes.
Turner Syndrome

Introduction: Short stature and delayed puberty characterize Turner syndrome (TS). The 2024 international clinical practice guidelines recommend growth hormone (GH) for latediagnosed patients if epiphyses remain open. For patients with remaining growth potential, initiating GH alongside low-dose estrogen effectively balances linear growth with the need for timely pubertal induction. Case: A 15-year-old female, born prematurely at 6 months gestation, presented with delayed puberty, primary amenorrhea, and short stature. Examination revealed a height of 122 cm (<5th percentile), weight of 26 kg, with no syndromic facies, and Tanner stage 1. Investigations confirmed hypergonadotropic hypogonadism. Metabolic screening, including thyroid, renal, and liver profile, was normal. Her baseline insulin-like growth factor 1 (IGF-1) was low at 117.5 ng/mL (127.5–541.5). Karyotyping confirmed mosaic TS (45,X/46,Xr). Her skeletal bone age was delayed at 12 years, indicating a viable window for linear growth prior to complete epiphyseal fusion. Subcutaneous GH was initiated at 0.3 mg up titrated to 1.2 mg (0.45 µg/kg) daily over 4 weeks, then 1.35 mg (50 µg/kg) daily at month 5. Low-dose oral estradiol (0.5 mg three times weekly) was introduced for pubertal induction at month 4. After 9 months of combined GH and estrogen therapy, the patient achieved a height increment of 6 cm, reaching 128 cm without an adverse event. To achieve the clinical target of a 10–15 cm increment in the first year, her GH dose was further increased to 1.50 mg (55 µg/kg) daily. She showed an appropriate biochemical response with IGF-1 increased to 40.2 nmol/L (16.4–67.8) with a total height gain of 6 cm over the first 9 months of GH therapy. Conclusion Concomitant GH and estrogen therapy in late-diagnosed TS successfully induced clinically significant height gain. This dual approach maximized the limited window for linear growth, without delaying pubertal induction and compromising patient’s psychosocial well-being.
Turner Syndrome

Introduction: Endocrine abnormalities are frequently observed in children with Down syndrome, with thyroid dysfunction being the most common. The distribution and patterns of thyroid disorders vary between populations. Methodology: Retrospective data were collected from the electronic medical records of children with Down syndrome who attended the paediatric clinic at University Malaya Medical Centre from the year 2000 to 2025. Data were analyzed to determine the frequency and distribution of thyroid disorders in this cohort. Results: The study included 57 patients, the majority of whom were identified through routine screening (n = 56, 98.2%). Only one child (1.8%) was diagnosed following a symptomatic presentation of diarrhea. Within the cohort, 51 patients were diagnosed with hypothyroidism and six with hyperthyroidism. Among those with hypothyroidism, the mean TSH was 22.5 mIU/L, with a median age at presentation of 61 days (IQR: 19–211.5). Notably, 25% of the cohort presented within the first 19 days, while the rest presented after 7 months of age. Of these, 24 cases (47.1%) were transient, with medications successfully discontinued at a mean age of 4.0 ± 2.13 years. Only 26 patients underwent thyroid scan, which was normal except for one case of thyroid agenesis. Imaging was not performed in others due to early discontinuation of therapy or loss to follow-up. All hyperthyroid patients had autoimmune thyroid disease (4 Graves’ disease, 2 Hashimoto’s thyroiditis) with positive autoantibodies. The median age at presentation was 5.4 years (IQR: 2.3–10.2). Conclusion Screening for thyroid dysfunction successfully identified almost all cases in patients with Down syndrome. Notably, patients which hyperthyroidism in this cohort had co-occurring autoimmune thyroid dysfunction and demonstrated a significantly earlier age of presentation compared to the general paediatric population.
Child ; Down Syndrome ; Thyroid Gland

Introduction: Children with Down syndrome (DS) have a higher prevalence of hypothyroidism compared to the general population, and both conditions are linked to impaired growth. This study aimed to determine the prevalence and subtypes of hypothyroidism in DS and to compare growth outcomes with controls from general population at 2 years of age. Methodology: A retrospective review was conducted on 248 children with DS (aged 2–18 years) followed at Hospital Pakar Universiti Sains Malaysia from 2020 to 2025. Growth outcomes were analyzed in a subgroup of 41 DS children with hypothyroidism compared to 46 controls. Growth was compared using standard CDC charts for and z -scores calculated with PediTools (CDC 2–20 age). Mid-parental height, target height attainment, and height velocity were evaluated. Statistical analysis used t-tests and chi-square tests (p <0.05). Results: Of the 248 children with DS, 63.7% had hypothyroidism, predominantly subclinical (85.4%). No cases of acquired or secondary hypothyroidism were found. Children with DS had significantly lower mean height z-scores (−1.91 ± 1.45 vs. −0.54 ± 1.25; p <0.001), borderline lower height velocity (5.80 ± 2.15 vs. 6.92 ± 3.56 cm/year; p = 0.050), and fewer achieved target height (35% vs. 64.1%; p = 0.030) compared to controls. Baseline characteristics were similar between groups. Thyroid ultrasound showed normal anatomy in 50%, hypoplasia in 28.6%, and nodules in 21.4%. Common comorbidities included congenital heart disease (78.4%), pulmonary complications (16.2%), and other anomalies (32.4%). Conclusion Subclinical hypothyroidism was the predominant subtype in DS. Affected children demonstrated poorer growth, with reduced height z-scores, slower growth velocity, and lower likelihood of achieving target height.
Humans ; Down Syndrome ; Prevalence ; Hypothyroidism

Introduction: ABCD syndrome (ABnormal Calcium-CreatinineCalcinosis in Down syndrome) is a rare tetrad of hypercalcemia, hypercalciuria, nephrocalcinosis, and renal impairment in children with Down syndrome, often with delayed diagnosis resulting in irreversible renal damage. : We report a 7-year-old male with Down syndrome, who previously had a stormy neonatal period due to large atrialseptal-defect and pulmonary hypertension, and required surgery at 3-years-old with prior prolonged ventilation. He was since bedbound with severe spastic diplegia, complicated by GERD and food aversion, requiring nasogastric tube feeding. He was discovered to have hypercalcemia and renal impairment during admission in district hospital for febrile illness with gastrointestinal symptoms. Initial serum calcium was 2.78 mmol/L, phosphate 1.54 mmol/L, magnesium 0.96 mmol/L, ALP 210 IU/L, urea 18.6 mmol/L, and creatinine 266 umol/L. Renal impairment did not improve and ultrasound KUB revealed bilateral small kidneys with medullary nephrocalcinosis. Consultation with the paediatric nephrologist concluded as CKDstage-4. He was transferred to our centre. He demonstrated severe hypercalcemia (3.44 mmol/L), hypercalciuria (urinecalcium-to-creatinine-ratio of 1.17 mmol/mmol, >95 th%), and suppressed iPTH (0.9 pmol/L,1.6–6.9), suggesting PTH-independent process. 25-OH-Vit-D3 was 134 nmol/L (74–250, sufficient). He was more irritable and moody, but no seizures. ECG was normal. Skeletal assessment did not reveal osteolytic changes or increased resorption. He was investigated by paediatric hemato-oncologists, with negative findings, despite extensive search for hematological or bone malignancy and granulomatous disease. His ESR and immunoglobulin level was high for unknown reasons. He was treated with intravenous and oral hydration, dietary calcium restriction with modified lowcalcium formula, assisted by dietitian, and IV pamidronate infusion (0.125 mg/kg) stat dose, resulting in stabilization of serum calcium level (2.5 mmol/L), which persisted for about 8 weeks during follow-up. Conclusion ABCD syndrome should be considered in Down syndrome children presenting with unexplained hypercalcemia. Early recognition and intervention are vital.
ABCD syndrome ; Down Syndrome ; Hypercalcemia

BACKGROUND

Down syndrome or trisomy 21, the most common chromosomal disorder, results from the presence of a third copy of chromosome 21 and manifests as mild to moderate intellectual disability, growth retardation, congenital heart defects, gastrointestinal abnormalities, and characteristic facial features. Several methods have been used to screen for Down syndrome in the prenatal period, such as ultrasound, biomarkers, cell-free DNA testing, and combinations of these tests. A positive result from one or more of these screening tests signals the need for confirmatory karyotyping to clinch the diagnosis. Ultrasound between 11 to 14 weeks of gestation can evaluate nuchal translucency (NT) to screen for Down syndrome. During the second trimester, a triple or quadruple test can also be performed alone or in addition to NT to quantify Down syndrome risk. In limited resource settings however, only the measurement of NT via ultrasound can be performed since biomarker tests are either unavailable or inaccessible. While the diagnostic performance of NT measurement alone has been investigated in several observational studies, there is no consensus on its performance as a sole test to screen for Down syndrome.

To determine the diagnostic performance of NT during prenatal first-trimester ultrasound as a screening test for Down syndrome.

We performed a systematic search on the PubMed, ProQuest, and Cochrane Library databases for recent systematic reviews and meta-analyses that addressed the objective. The existing reviews found were then independently appraised by the two reviewers with the AMSTAR-2 checklist. To update the existing reviews, a systematic search was done in the same databases to identify additional primary diagnostic studies, which were appraised using the QUADAS-2 tool. Random-effects univariate meta-analysis and summary receiving operator curve (HSROC) analysis for the outcomes were performed using Review Manager version 5.4 and R version 4.2.2, respectively. Subgroup analysis was performed by stratifying the baseline risk of mothers for fetal anomaly as low- or high-risk. Highrisk mothers were defined as women with risk factors such as advanced age, positive serum screen, presence of other ultrasound anomalies, and history of previous fetus with anomaly.

We found 22 cohort studies (n=225,846) of women at low-risk for fetal anomaly. The pooled sensitivity was 67.8% (95% CI: 61.4%-73.6%, I2=70.4%) and specificity was 96.3% (95% CI: 95.5%-96.9%, I2=96.7%). For low-risk women, the overall certainty of evidence was low, due to different modes of verification and heterogeneity not completely explained by variability in baseline risk or cut-points. Seven studies (n=9,197) were on high-risk women. The pooled sensitivity was 62.2% (95% CI: 54.1%-69.7%, I2=38.8%) and specificity was 96.5% (95% CI: 93.6%-98.1%, I2=95.5%). For women at high-risk, the evidence was rated as moderate due to differential verification.

Our analysis showed that NT measured through first-trimester ultrasound is specific for Down syndrome but has low sensitivity. Despite this, it is a useful screening test for Down syndrome in low-resource settings where other strategies may not be available or accessible. Furthermore, interpretation of NT results must take into consideration its limited sensitivity as this may lead to missed cases.

BACKGROUND

Down syndrome or trisomy 21, the most common chromosomal disorder, results from the presence of a third copy of chromosome 21 and manifests as mild to moderate intellectual disability, growth retardation, congenital heart defects, gastrointestinal abnormalities, and characteristic facial features. Several methods have been used to screen for Down syndrome in the prenatal period, such as ultrasound, biomarkers, cell-free DNA testing, and combinations of these tests. A positive result from one or more of these screening tests signals the need for confirmatory karyotyping to clinch the diagnosis. Ultrasound between 11 to 14 weeks of gestation can evaluate nuchal translucency (NT) to screen for Down syndrome. During the second trimester, a triple or quadruple test can also be performed alone or in addition to NT to quantify Down syndrome risk. In limited resource settings however, only the measurement of NT via ultrasound can be performed since biomarker tests are either unavailable or inaccessible. While the diagnostic performance of NT measurement alone has been investigated in several observational studies, there is no consensus on its performance as a sole test to screen for Down syndrome.

To determine the diagnostic performance of NT during prenatal first-trimester ultrasound as a screening test for Down syndrome.

We performed a systematic search on the PubMed, ProQuest, and Cochrane Library databases for recent systematic reviews and meta-analyses that addressed the objective. The existing reviews found were then independently appraised by the two reviewers with the AMSTAR-2 checklist. To update the existing reviews, a systematic search was done in the same databases to identify additional primary diagnostic studies, which were appraised using the QUADAS-2 tool. Random-effects univariate meta-analysis and summary receiving operator curve (HSROC) analysis for the outcomes were performed using Review Manager version 5.4 and R version 4.2.2, respectively. Subgroup analysis was performed by stratifying the baseline risk of mothers for fetal anomaly as low- or high-risk. Highrisk mothers were defined as women with risk factors such as advanced age, positive serum screen, presence of other ultrasound anomalies, and history of previous fetus with anomaly.

We found 22 cohort studies (n=225,846) of women at low-risk for fetal anomaly. The pooled sensitivity was 67.8% (95% CI: 61.4%-73.6%, I2=70.4%) and specificity was 96.3% (95% CI: 95.5%-96.9%, I2=96.7%). For low-risk women, the overall certainty of evidence was low, due to different modes of verification and heterogeneity not completely explained by variability in baseline risk or cut-points. Seven studies (n=9,197) were on high-risk women. The pooled sensitivity was 62.2% (95% CI: 54.1%-69.7%, I2=38.8%) and specificity was 96.5% (95% CI: 93.6%-98.1%, I2=95.5%). For women at high-risk, the evidence was rated as moderate due to differential verification.

Our analysis showed that NT measured through first-trimester ultrasound is specific for Down syndrome but has low sensitivity. Despite this, it is a useful screening test for Down syndrome in low-resource settings where other strategies may not be available or accessible. Furthermore, interpretation of NT results must take into consideration its limited sensitivity as this may lead to missed cases.