Primordial dwarfism (PD) refers to a group of monogenic genetic disorders characterized by intrauterine growth restriction (IUGR) and severe, persistent postnatal growth retardation. These diseases have been associated with variants of multiple genes whose products are mainly involved in critical cellular biological processes such as maintenance of genomic stability, DNA damage repair, mRNA splicing regulation, and centrosome function. Variants of such genes can directly impair cell proliferation and developmental potential. With the widespread application of molecular genetic technologies such as high-throughput sequencing, significant progress has been made in the research of PD. This article focuses on the major subtypes of PD, including Seckel syndrome, Microcephalic osteodysplastic primordial dwarfism (MOPD) types I/III, MOPD type II, and Meier-Gorlin syndrome. It has systematically summarized the advances in their clinical phenotypic characteristics, pathogenic genes, and molecular mechanisms, with an aim to deepen the understanding of the essence of growth disorders associated with PD.
Humans ; Dwarfism/genetics* ; Microcephaly/genetics* ; Phenotype ; Fetal Growth Retardation/genetics* ; Osteochondrodysplasias/genetics* ; Growth Disorders ; Micrognathism ; Patella/abnormalities* ; Congenital Microtia

OBJECTIVE: To analyze the phenotype and genotype of a neonate with Osteo-oto-hepato-enteric syndrome (O2HE) and review the literature. METHODS: A female neonate diagnosed with O2HE syndrome on December 13, 2024 at the First Affiliated Hospital of Zhengzhou University was selected as the study subject, and her clinical characteristics were analyzed, and pathogenic variants were explored by whole exome sequencing (WES). This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: 2025-KY-1038). RESULTS: The proband, a female infant, was delivered by Cesarean section at 36⁺¹ weeks of gestation. Five days after birth, she had developed severe diarrhea, mild cholestasis, sensorineural hearing loss, and growth retardation. WES revealed that she has harbored novel compound heterozygous variants c.512delA (p.Lys171Serfs*64) and c.698C>A (p.Thr233Asn) of the UNC45A gene, which were inherited from her mother and father, respectively. A total of 8 English papers were retrieved, which involved 16 patients from 14 families. Combined with our case, the 17 patients included 13 (76.5%) females and 4 (23.5%) males. Four patients (23.5%) had consanguineous parents. One case was excluded from further genetic analysis due to co-morbidity with other genetic variants. The primary clinical features included diarrhea (87.5%), cholestasis (81.3%), sensorineural hearing loss (31.3%), bone fragility (37.5%), and developmental delay (50.0%). Bi-allelic compound heterozygous mutations were identified in 12 patients (75.0%), and homozygous variants in 4 (25.0%). These included missense, nonsense, frameshift and deletional variants. The c.710T>C (p.Leu237Pro) variant was identified for 5 times, 3 of which were in homozygote forms. CONCLUSION O2HE syndrome should be suspected in cases with diarrhea, cholestasis, and hearing abnormalities during early postnatal period. Genetic testing facilitate early identification, genetic diagnosis and treatment.
Humans ; Female ; Infant, Newborn ; Male ; Mutation ; Hearing Loss, Sensorineural/genetics* ; Diarrhea, Infantile/genetics* ; Exome Sequencing ; Phenotype ; Fetal Growth Retardation ; Hair Diseases ; Facies

OBJECTIVES: To investigate the readmission rate and risk factors for readmission due to hyperbilirubinemia in neonates with ABO hemolytic disease of the newborn (ABO-HDN), and to construct a risk prediction model for readmission. METHODS: Neonates diagnosed with hyperbilirubinemia due to ABO-HDN and hospitalized in the neonatal department between January 2021 and December 2023 were enrolled. Based on readmission status, neonates were divided into a readmission group and a control group. Clinical characteristics related to hyperbilirubinemia and risk factors for readmission were analyzed. Subsequently, a prediction model for readmission was constructed, and its predictive performance was evaluated. RESULTS: A total of 483 neonates with hyperbilirubinemia due to ABO-HDN were included. The readmission rate was 13.0% (63 cases). Multivariate logistic regression analysis revealed that earlier age at phototherapy initiation, longer duration of phototherapy, occurrence of rebound hyperbilirubinemia, and higher levels of serum total bilirubin and indirect bilirubin at discharge were independent risk factors for hyperbilirubinemia readmission in ABO-HDN neonates (OR=2.373, 4.840, 6.475, 5.033, 1.336 respectively; P<0.05). A risk prediction model for ABO-HDN hyperbilirubinemia readmission was constructed based on these 5 risk factors. Model evaluation demonstrated good predictive performance. CONCLUSIONS Age at phototherapy initiation, duration of phototherapy, occurrence of rebound hyperbilirubinemia, and serum total bilirubin and indirect bilirubin levels at discharge are significant influencing factors for readmission due to hyperbilirubinemia in neonates with ABO-HDN. Close monitoring during discharge planning and follow-up management for such neonates is crucial to reduce readmission rates.
Humans ; Infant, Newborn ; ABO Blood-Group System ; Risk Factors ; Patient Readmission ; Male ; Female ; Logistic Models ; Hyperbilirubinemia, Neonatal/therapy* ; Erythroblastosis, Fetal ; Bilirubin/blood*

OBJECTIVE: To analyze the laboratory detection results of hemolytic disease of the fetus and newborn(HDFN). METHODS: Related test results of 283 newborns and their mothers' blood samples from Kunming Maternal and Child Health Hospital from August 2023 to May 2024 were collected, including mother and child ABO blood group, RhD blood group, as well as 3 tests of HDFN, total bilirubin (TBil) and indirect bilirubin (IBil). RESULTS: 283 were ABO incompatibility, among which 187 were HDFN positive, with a positive rate of 66.08%; the positive rate of HDFN in neonates with antigen-A incompatibility was 74.12%(126/170), the positive rate of HDFN in neonates with antigen-B incompatibility was 53.57%(60/112), which was the highest in neonates with O/A incompatibility ［75.45%(126/167)］, followed by O/B incompatibility［54.55%(60/110)］. Group by age, the positive rates of HDFN in the ≤1 d group, 2 d group, 3 d group, 4 d group, 5 d group and ≥6 d group were 76.03%(111/146), 67.86%(38/56), 57.14%(24/42), 38.46%(5/13), 46.15%(6/13) and 23.08%(3/13), respectively. With the increase of age, the positive rates of HDFN gradually decreased, there was a statistically significant difference between the ≤3 day age group and >3 day age group ( P <0.05). There was no statistically significant difference in TBil and IBil levels between the "direct antibody+indirect antibody+release+" group and the HDFN negative group in newborns. HDFN infants exhibited a rapid increase in bilirubin levels within the first day after birth, with significantly higher TBil and IBil values compared to Non ABO-HDFN infants in the ≤1 day group ( P <0.01). However, the difference of bilirubin levels between the two groups gradually narrowed from 2-6 days after birth, and the difference was not statistically significant (P >0.05). The peak value of TBil and IBil occurred on the 4th day after birth in HDFN infants. CONCLUSION ABO-HDFN is most commonly seen in newborns whose mothers are type-O, and the positive rate was the highest in newborns with O/A incompatibility. The detection rate of HDFN is affected by the age of the newborns, and the two were correlated inversely. ABO-HDFN group developed more rapidly with a higher peak. Therefore, HDFN tests should be carried out as soon as possible for mothers and newborns with incompatible blood types, and appropriate treatment should be provided to prevent complications.
Humans ; Infant, Newborn ; ABO Blood-Group System ; Erythroblastosis, Fetal/epidemiology* ; Female ; China/epidemiology* ; Blood Group Incompatibility ; Male ; Bilirubin/blood*

OBJECTIVE: To explore the clinical features and genetic etiology of a child with Hoyeraal-Hreidarsson syndrome (HHS). METHODS: A child with HHS diagnosed at the Affiliated Hospital of Jining Medical University due to "developmental delay and anaemia" on April 27, 2024 was selected as the study subject. Clinical data of the child was collected. Genomic DNA was extracted from peripheral blood samples of the child and his family members. Whole-exome sequencing was carried out, and candidate variant was verified by Sanger sequencing of his family members and bioinformatics analysis using CASAVA v1.8.2. The pathogenicity of the candidate variant was rated according to the Standards and Guidelines for the Interpretation of Sequence Variants released by the American College of Medical Genetics and Genomics (ACMG). Relevant literature on HHS cases reported in China was reviewed to analyze the clinical and genetic characteristics. This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: 2024-10-C003). RESULTS: The child, a 7-month-old boy, had mainly manifested with growth retardation, developmental delay, microcephaly, cerebellar hypoplasia, immunodeficiency and bone marrow failure. Routine blood test indicated pancytopenia. The immunological workup showed reduction of B cells, NK cells and immunoglobulins. Cranial MRI demonstrated the volume of bilateral cerebellar hemispheres and brainstem and corpus callosum was small. Whole-exome sequencing revealed that he has harbored a hemizygous c.103_105del (p.Glu35del) variant of the DKC1 gene. Sanger sequencing showed that his mother and two sisters have carried the same variant. Based on the ACMG guidelines, the variant was predicted to be likely pathogenic (PM1+PM4+PS4_Supporting+PM2_Supporting). Four relevant literature were retrieved, which has involved 8 HHS cases. Together with the patient from this study, they have consisted of 8 males and 1 females. The most common symptoms of the 9 patients were blood system abnormalities and developmental delay. All patients had shown cerebellar dysplasia and anemia/erythrocytopenia. Among them, 3 cases have harbored TINF2 gene variants, and 6 cases had harbored DKC1 gene variants. The c.103_105del variant has not been reported in China previously. CONCLUSION The hemizygous c.103_105del (p.Glu35del) variant of the DKC1 gene probably underlay the disease in this child. Above finding has expanded the mutational and phenotypic spectra of the DKC1 gene, and has facilitated early diagnosis of HHS in this child.
Humans ; Infant ; Male ; Cell Cycle Proteins/genetics* ; Dyskeratosis Congenita/genetics* ; Exome Sequencing ; Fetal Growth Retardation/genetics* ; Intellectual Disability/genetics* ; Microcephaly/genetics* ; Mutation ; Nuclear Proteins/genetics* ; X-Linked Intellectual Disability/genetics*

OBJECTIVE: To carry out pathological and genetic analyses on a fetus with intrauterine growth restriction and death during second trimester after induced abortion. METHODS: A fetus undergone induced abortion due to intrauterine growth restriction and death during second trimester at the the Seventh Affiliated Hospital of Sun Yat-Sen University in 2024 was selected as the study subject. Clinical data of the pregnancy were collected. DNA was extracted from tissues from the aborted fetus and peripheral blood samples from its parents. Chromosomal microarray analysis and whole exome sequencing were carried out. Candidate variants were verified by Sanger sequencing. Following abortion, routine autopsy and pathological analysis were conducted. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: KY-2025-334-01). RESULTS: The aborted fetus was a male and harbored compound heterozygous nonsense variants of the TH gene (c.457C>T/p.Arg153* and c.694C>T/p.Gln232*), for which both parents were heterozygous carriers. Autopsy and pathological analysis revealed that the fetus had pathological features including loose arrangement of myocardial fibers and congestion in the liver. CONCLUSION Biallelic null variants of the TH gene may cause heart failure by affecting the development of cardiovascular system, which in turn may lead to intrauterine death. This study has provided new clues for the molecular diagnosis of stillbirth and recurrent pregnancy loss.
Humans ; Female ; Pregnancy ; Male ; Heterozygote ; Codon, Nonsense/genetics* ; Fetal Growth Retardation/pathology* ; Adult ; Stillbirth/genetics*

MIRAGE syndrome is a rare autosomal dominant disorder caused by gain-of-function mutations of the SAMD9 gene. Its typical clinical manifestations include myelodysplasia, intrauterine growth restriction, adrenal hypoplasia, genital abnormalities, and enteropathy. The gain-of-function toxicity of the SAMD9 gene and subsequent somatic revertant mutations have been identified as the core molecular mechanisms underlying the multi-system phenotypes and clonal hematopoietic evolution in this disease. The specific genotypic background and tissue-specific distribution of somatic revertant mutations collectively constitute the genetic basis for its significant clinical heterogeneity. In recent years, important breakthroughs have been made in research on the pathogenesis, phenotypic expansion, molecular diagnosis, and targeted therapy of the MIRAGE syndrome. This article has systematically reviewed the latest progress made in the research on the etiology, clinical manifestations, diagnosis, and treatment of this disease.
Humans ; Mutation ; Fetal Growth Retardation/therapy* ; Myelodysplastic Syndromes/therapy* ; Intracellular Signaling Peptides and Proteins/genetics*

Objective: The objective of this study was to evaluate and compare the global cardiac sphericity index (GCSI) of appropriate for gestational age (AGA) fetuses, small for gestational age (SGA) fetuses, and growth-restricted fetuses scanned at term in a government tertiary hospital, maternal high risk (MHR) and to determine the association between the GCSI of these three groups of fetuses and their neonatal outcomes. Methodology: The study prospectively evaluated and compared the GCSI of AGA, SGA, and growth-restricted fetuses. Pregnant women at term seen at the outpatient department and scanned at the MHR clinic then eventually delivered in the same hospital from March to May 2022 were included in this study. Results: GCSIs were measured with 147 fetuses (106 AGA, 38 SGA, and 3 growth‑restricted fetuses). The result indicated that the GCSI of AGA fetuses was higher than that of the SGA and growth‑restricted fetuses. This study found that there is a significantly higher frequency of abnormal GSCI among SGA and growth‑restricted fetuses. This study also found that there is no statistically significant correlation between the GCSI measurements of these three groups of fetuses and their neonatal outcomes. Conclusions Abnormal GCSIs were found in fetuses with an estimated fetal weight <10th percentile (more specifically in growth‑restricted fetuses than in those who are just SGA) as compared with AGA fetuses. However, the correlation between an abnormal GCSI in any of these three groups of fetuses and their neonatal outcomes needs further investigation.
Fetal Growth Retardation

OBJECTIVE: To carry out genetic analysis for a fetus with confined placental mosaicism (CPM) for trisomy 2 (T2) in conjunct with fetal uniparental disomy (UPD). METHODS: Amniocentesis and chromosomal karyotyping was carried out for a pregnant woman with a high risk for chromosome 2 anomalies indicated by non-invasive prenatal testing (NIPT). Single nucleotide polymorphism array (SNP-array) and trio-whole exome sequencing (Trio-WES) were carried out. Ultrasonography was used to closely monitor the fetal growth. Multifocal sampling of the placenta was performed after delivery for copy number variation sequencing (CNV-seq). RESULTS: The fetus was found to have a normal chromosomal karyotype. SNP-array has revealed multiple regions with loss of heterozygosity (LOH) on chromosome 2. Trio-WES confirmed the presence of maternal UPD for chromosome 2. Ultrasonography has revealed intrauterine growth restriction and oligohydramnios. Intrauterine fetal demise had occurred at 23⁺⁴ weeks of gestation. Pathological examination had failed to find salient visceral abnormality. The placenta was proved to contain complete T2 by CNV-seq. CONCLUSION T2 CPM can cause false positive result for NIPT and may be complicated with fetal UPD, leading to adverse obstetric outcomes such as intrauterine growth restriction, oligohydramnios and intrauterine fetal demise.
Female ; Humans ; Pregnancy ; Amniocentesis ; Chromosomes, Human, Pair 2/genetics* ; DNA Copy Number Variations ; Fetal Death ; Fetal Growth Retardation/genetics* ; Fetus ; Mosaicism ; Oligohydramnios ; Placenta ; Trisomy/genetics* ; Uniparental Disomy/genetics*

OBJECTIVES: To study the left heart structure and functional characteristics of term neonates with intrauterine growth restriction (IUGR). METHODS: This study included 86 term neonates with IUGR admitted to the Neonatal Ward of Beijing Friendship Hospital, Capital Medical University from January 2019 to January 2022 as the IUGR group, as well as randomly selected 86 term neonates without IUGR born during the same period as the non-IUGR group. The clinical data and echocardiographic data were compared between the two groups. RESULTS: The analysis of left heart structure and function showed that compared with the non-IUGR group, the IUGR group had significantly lower left ventricular mass, left ventricular end-diastolic diameter, left ventricular end-systolic diameter, left atrial diameter, end-diastolic interventricular septal thickness, left ventricular posterior wall thickness, left ventricular end-diastolic volume, left ventricular end-systolic volume, and stroke volume (P<0.05) and significantly higher ratio of end-diastolic interventricular septal thickness to left ventricular posterior wall thickness, proportion of neonates with a mitral peak E/A ratio of ≥1, and cardiac index (P<0.05). The Spearman correlation analysis suggested that stroke volume was positively correlated with birth weight and body surface area (r_s=0.241 and 0.241 respectively; P<0.05) and that the ratio of end-diastolic interventricular septal thickness to left ventricular posterior wall thickness was negatively correlated with birth weight and body surface area (r_s=-0.229 and -0.225 respectively; P<0.05). CONCLUSIONS The left ventricular systolic function of neonates with IUGR is not significantly different from that of neonates without IUGR. However, the ventricular septum is thicker in neonates with IUGR. This change is negatively correlated with birth weight and body surface area. The left ventricular diastolic function may be impaired in neonates with IUGR.
Humans ; Infant, Newborn ; Birth Weight ; Echocardiography ; Fetal Growth Retardation ; Heart ; Heart Ventricles/diagnostic imaging* ; Ventricular Function, Left