Abnormal Auditory Mismatch Fields in Children and Adolescents with 47,XYY Syndrome

Can Individuals with 47,XYY Karyotypes Exist without Male Phenotype? A Narrative Literature Review and Case Report

BACKGROUND

The 47,XYY syndrome is a genetic condition found in about 1 in 1000 male children. The expected phenotype is male but could vary greatly. Those with genitourinary abnormalities may also present with microphallus, hypoplastic scrotum, cryptorchidism, hypospadias and macroorchidism. This study reports a child with sex ambiguity who possesses an initial 47,XYY karyotype. We also conducted a narrative literature review of 47,XYY individuals and their respective genital phenotype and/or gender identity.

METHODS

The narrative literature review was performed by searching for "47,XYY" in the PubMed database. All studies published in English, Spanish or Portuguese from January 1960 to January 2024 that contained the term "47,XYY" in the title or abstract were included. Studies that did not describe the genital phenotype and/or gender identity of cases were excluded. We also described the case of a 2-month-old patient with the 47,XYY karyotype and sex ambiguity.

RESULTS

Our patient underwent additional karyotype testing, resulting in 47,XYY [30] and another 45,X [2]/47,XYY [98] with mosaicism being confirmed by fluorescent in situ hybridization (FISH) on buccal smears (nuc ish (DXZ1 × 1, DYZ3 × 2)[64/100]/(DXZ1 × 1, DYZ3 × 0)[36/100]. A gonadal biopsy revealed an atrophic testis on the left and a streak gonad on the right, with a final diagnosis of mixed gonadal dysgenesis determined. The narrative review revealed 643 articles, of which 350 met the inclusion criteria. However, we excluded 132 articles because they presented no new cases. We included 138 articles, which presented a series containing less than 10 new cases with the 47,XYY karyotype (total of 327 cases), 58 articles presented 4001 cases and 22 articles presented 75 patients with the 47,XYY karyotype in mosaic with 45,X. For all 4403 analyzed cases, 4354 (98.90%) presented a male phenotype, of which 4322 had the 47,XYY karyotype and 32 had mosaicism with 45,X lineage. A further 23 (0.52%) presented a female phenotype, of which four had the 47,XYY karyotype and 19 had mosaicism with 45,X lineage. In addition, 23 (0.52%) cases presented ambiguous genitalia, of which two had the 47,XYY karyotype and 21 had mosaicism with 45,X lineage. Finally, three (0.06%) cases had undefined phenotypes, all with mosaicism with 45,X lineage. Of the six cases with the 47,XYY karyotype and no male phenotype, one had complete androgen insensitivity syndrome (CAIS), one had lipoid congenital adrenal hyperplasia, two had probable CAIS, and two presented an incomplete diagnostic investigation.

CONCLUSIONS

A female or ambiguous genital phenotype in an individual with 47,XYY karyotype is uncommon and should alert to the presence of the 45,X lineage or association with other causes of disorder/difference of sex development.

Preimplantation genetic testing might not be the necessity for male patients with 47,XYY syndrome: A pilot study

Purpose

This pilot study aimed to explore the necessity for 47,XYY syndrome males (couples) to perform PGT rather than conventional In Vitro Fertilization (IVF)/Intracytoplasmic Sperm Injection (ICSI) cycles.

Methods

A retrospective cohort study was conducted with 36 nonmosaic and mosaic 47,XYY syndrome patients (couples) undergoing 43 oocyte retrieval cycles (37 planned for PGT and 6 for IVF/ICSI) between December 2017 and December 2023. The couples were given either next-generation sequencing-based PGT or conventional IVF/ICSI followed by 45 embryo transfer (ET) cycles (38 from PGT and 7 from IVF/ICSI). The detailed cytogenetic results of the 129 embryos from PGT were analyzed, and the pregnancy and neonatal outcomes between PGT-ET and conventional IVF/ICSI-ET cycles were compared.

Results

The PGT results showed that the chance of sex chromosome abnormalities was low (1.55%), with chromosomal errors being observed more often in autosomes. Importantly, no differences were observed in the rates of biochemical pregnancy, implantation, clinical pregnancy, ongoing pregnancy, pregnancy loss, live birth, and preterm delivery between PGT-ET cycles and conventional IVF/ICSI-ET cycles. Comparable results regarding gestational age, birthweight, low birthweight rate, macrosomia rate, male rate, as well as the rate of congenital anomalies were also observed between the two groups.

Conclusions

Preimplantation genetic testing might not be necessary to conduct for 47,XYY syndrome males unless there are other indications. Studies with large populations are in demand to confirm the present results.

Genetic outcomes in children with developmental language disorder: a systematic review

Introduction

Developmental language disorder (DLD) is a common childhood condition negatively influencing communication and psychosocial development. An increasing number of pathogenic variants or chromosomal anomalies possibly related to DLD have been identified. To provide a base for accurate clinical genetic diagnostic work-up for DLD patients, understanding the specific genetic background is crucial. This study aims to give a systematic literature overview of pathogenic variants or chromosomal anomalies causative for DLD in children.

Methods

We conducted a systematic search in PubMed and Embase on available literature related to the genetic background of diagnosed DLD in children. Included papers were critically appraised before data extraction. An additional search in OMIM was performed to see if the described DLD genes are associated with a broader clinical spectrum.

Results

The search resulted in 15,842 papers. After assessing eligibility, 47 studies remained, of which 25 studies related to sex chromosome aneuploidies and 15 papers concerned other chromosomal anomalies (SCAs) and/or Copy Number Variants (CNVs), including del15q13.1-13.3 and del16p11.2. The remaining 7 studies displayed a variety of gene variants. 45 (candidate) genes related to language development, including FOXP2, GRIN2A, ERC1, and ATP2C2. After an additional search in the OMIM database, 22 of these genes were associated with a genetic disorder with a broader clinical spectrum, including intellectual disability, epilepsy, and/or autism.

Conclusion

Our study illustrates that DLD can be related to SCAs and specific CNV's. The reported (candidate) genes (n = 45) in the latter category reflect the genetic heterogeneity and support DLD without any comorbidities and syndromic language disorder have an overlapping genetic etiology.

Towards Biomarkers for Autism Spectrum Disorder: Contributions of Magnetoencephalography (MEG)

There is no simple blood test for autism. Consequently, much attention has been paid to identifying noninvasive biomarkers using imaging (e.g., Magnetic resonance imaging, MRI) and electrophysiological (e.g., electroencephalography, EEG and magnetoencephalography, MEG) methods. While, in general, these lack direct biological specificity, they can (in principle) provide a useful tool, or suite of tools, for diagnostic, prognostic, stratification, and response monitoring purposes.This chapter focuses on the pursuit of biomarkers using magnetoencephalography (MEG). While closely related to the more common electroencephalography (EEG), MEG offers some unique characteristics (such as improved spatial resolution, in combination with real-time temporal resolution and spectral discrimination), that might be considered impactful in the pursuit of biomarkers.Given the widely-acknowledged heterogeneity of ASD ("if you've seen one child with autism, then you've seen one child with autism"), the tide of research is perhaps shifting away from diagnostic biomarkers toward biomarkers that can help stratify patients according to some similarity in biological basis, etiology, or pathway. This approach, somewhat pragmatic, may be of benefit when designing and conducting clinical trials of putative therapeutics, or when optimally designing behavioral supports (when "therapy" may not be indicated).Ultimately, MEG-derived biomarkers, however advantageous in themselves, may likely find a place as reference in the prioritization and roll-out of candidate biomarkers established using other modalities, more accessible and available to the global community.

Comparison of evoked potentials across four related developmental encephalopathies

BACKGROUND

Developing biomarkers is a priority for drug development for all conditions, but vital in the rare neurodevelopmental disorders where sensitive outcome measures are lacking. We have previously demonstrated the feasibility and tracking of evoked potentials to disease severity in Rett syndrome and CDKL5 deficiency disorder. The aim of the current study is to characterize evoked potentials in two related developmental encephalopathies, MECP2 duplication syndrome and FOXG1 syndrome, and compare across all four groups to better understand the potential of these measures to serve as biomarkers of clinical severity for the developmental encephalopathies.

METHODS

Visual and auditory evoked potentials were acquired from participants with MECP2 duplication syndrome and FOXG1 syndrome across five sites of the Rett Syndrome and Rett-Related Disorders Natural History Study. A group of age-matched individuals (mean = 7.8 years; range = 1-17) with Rett syndrome, CDKL5 deficiency disorder, and typically-developing participants served as a comparison group. The analysis focused on group-level differences as well as associations between the evoked potentials and measures of clinical severity from the Natural History Study.

RESULTS

As reported previously, group-level comparisons revealed attenuated visual evoked potentials (VEPs) in participants with Rett syndrome (n = 43) and CDKL5 deficiency disorder (n = 16) compared to typically-developing participants. VEP amplitude was also attenuated in participants with MECP2 duplication syndrome (n = 15) compared to the typically-developing group. VEP amplitude correlated with clinical severity for Rett syndrome and FOXG1 syndrome (n = 5). Auditory evoked potential (AEP) amplitude did not differ between groups, but AEP latency was prolonged in individuals with MECP2 duplication syndrome (n = 14) and FOXG1 syndrome (n = 6) compared to individuals with Rett syndrome (n = 51) and CDKL5 deficiency disorder (n = 14). AEP amplitude correlated with severity in Rett syndrome and CDKL5 deficiency disorder. AEP latency correlated with severity in CDKL5 deficiency disorder, MECP2 duplication syndrome, and FOXG1 syndrome.

CONCLUSIONS

There are consistent abnormalities in the evoked potentials in four developmental encephalopathies some of which correlate with clinical severity. While there are consistent changes amongst these four disorders, there are also condition specific findings that need to be further refined and validated. Overall, these results provide a foundation for further refinement of these measures for use in future clinical trials for these conditions.

Profiling of Sexually Dimorphic Genes in Neural Cells to Identify Eif2s3y, Whose Overexpression Causes Autism-Like Behaviors in Male Mice

Many neurological disorders exhibit sex differences and sex-specific therapeutic responses. Unfortunately, significant amounts of studies investigating molecular and cellular mechanisms underlying these neurological disorders use primary cell cultures with undetermined sexes; and this may be a source for contradictory results among different studies and impair the validity of study conclusion. Herein, we comprehensively compared sexual dimorphism of gene expression in primary neurons, astrocytes, and microglia derived from neonatal mouse brains. We found that overall sexually dimorphic gene numbers were relatively low in these primary cells, with microglia possessing the most (264 genes), neurons possessing the medium (69 genes), and astrocytes possessing the least (30 genes). KEGG analysis indicated that sexually dimorphic genes in these three cell types were strongly enriched for the immune system and immune-related diseases. Furthermore, we identified that sexually dimorphic genes shared by these primary cells dominantly located on the Y chromosome, including Ddx3y, Eif2s3y, Kdm5d, and Uty. Finally, we demonstrated that overexpression of Eif2s3y increased synaptic transmission specifically in male neurons and caused autism-like behaviors specifically in male mice. Together, our results demonstrate that the sex of primary cells should be considered when these cells are used for studying the molecular mechanism underlying neurological disorders with sex-biased susceptibility, especially those related to immune dysfunction. Moreover, our findings indicate that dysregulation of sexually dimorphic genes on the Y chromosome may also result in autism and possibly other neurological disorders, providing new insights into the genetic driver of sex differences in neurological disorders.

Noninvasive prenatal testing for assessing foetal sex chromosome aneuploidy: a retrospective study of 45,773 cases

OBJECTIVE

To assess the positive predictive value (PPV) of noninvasive prenatal testing (NIPT) as a screening test for sex chromosome aneuploidy (SCA) with different maternal characteristics and prenatal decisions in positive cases.

MATERIALS AND METHODS

We retrospectively analysed 45,773 singleton pregnancies with different characteristics that were subjected to NIPT in the Maternity and Child Health Hospital of Anhui Province. The results were validated by karyotyping. Clinical data, diagnostic results, and data on pregnancy outcomes were collected.

RESULTS

In total, 314 cases were SCA positive by NIPT; among those, 143 underwent invasive prenatal diagnostic testing, and 58 were true-positive. Overall, the PPVs for 45,X, 47,XXX, 47,XXY and 47,XYY were 12.5%, 51.72%, 66.67% and 83.33%, respectively. Interestingly, when only pregnant women of advanced maternal age (AMA) were screened, the PPVs for 45,X, 47,XXX, 47,XXY and 47,XYY were 23.81%, 53.33%, 78.95%, and 66.67%, respectively. The frequency of SCA was significantly higher in the AMA group than in the non-AMA group. The frequencies of 47,XXX and 47,XXY were significantly correlated with maternal age.

CONCLUSION

NIPT performed better in predicting sex chromosome trisomies than monosomy X, and patients with 45,X positive foetuses were more eager to terminate pregnancy than those with 47,XXX and 47,XYY. AMA may be a risk factor of having a foetus with SCA. Our findings may assist in genetic counselling of AMA pregnant women. Our pre- and posttest counselling are essential for familiarizing pregnant women with the benefits and limitations of NIPT, which may ease their anxiety and enable them to make informed choices for further diagnosis and pregnancy decisions.

Magnetoencephalography Research in Pediatric Autism Spectrum Disorder

Magnetoencephalography (MEG) research indicates differences in neural brain measures in children with autism spectrum disorder (ASD) compared to typically developing (TD) children. As reviewed here, resting-state MEG exams are of interest as well as MEG paradigms that assess neural function across domains (e.g., auditory, resting state). To date, MEG research has primarily focused on group-level differences. Research is needed to explore whether MEG measures can predict, at the individual level, ASD diagnosis, prognosis (future severity), and response to therapy.

Abnormal Auditory Mismatch Fields in Children and Adolescents With 16p11.2 Deletion and 16p11.2 Duplication

BACKGROUND

Individuals with either deletion or duplication of the BP4-BP5 segment of chromosome 16p11.2 have varied behavioral phenotypes that may include autistic features, mild to moderate intellectual disability, and/or language impairment. However, the neurophysiological correlates of auditory language discrimination processing in individuals with 16p11.2 deletion and 16p11.2 duplication have not been investigated.

METHODS

Magnetoencephalography was used to measure magnetic mismatch fields (MMFs) arising from the left and right superior temporal gyrus during an auditory oddball paradigm with vowel stimuli (/a/ and /u/) in children and adolescents with 16p11.2 deletion or 16p11.2 duplication and in typically developing peers. One hundred twenty-eight participants ranging from 7 to 17 years of age were included in the final analysis (typically developing: n = 61, 12.08 ± 2.50 years of age; 16p11.2 deletion: n = 45, 11.28 ± 2.51 years of age; and 16p11.2 duplication: n = 22, 10.73 ± 2.49 years of age).

RESULTS

Delayed MMF latencies were found in both 16p11.2 deletion and 16p11.2 duplication groups compared with typically developing subjects. In addition, these delayed MMF latencies were associated with language and cognitive ability, with prolonged latency predicting greater impairment.

CONCLUSIONS

Our findings suggest that auditory MMF response delays are associated with clinical severity of language and cognitive impairment in individuals with either 16p11.2 deletion or 16p11.2 duplication, indicating a correlate of their shared/overlapping behavioral phenotype (and not a correlate of gene dosage).

CNVs and Chromosomal Aneuploidy in Patients With Early-Onset Schizophrenia and Bipolar Disorder: Genotype-Phenotype Associations

Introduction: Early-onset schizophrenia (EOS) and bipolar disorder (EOB) start before the age of 18 years and have a more severe clinical course, a worse prognosis, and a greater genetic loading compared to the late-onset forms. Copy number variations (CNVs) are an important genetic factor in the etiology of psychiatric disorders. Therefore, this study aimed to analyze CNVs in patients with EOS and EOB and to establish genotype-phenotype relationships for contiguous gene syndromes or genes affected by identified CNVs. Methods: Molecular karyotyping was performed in 45 patients, 38 with EOS and seven with EOB hospitalized between 2010 and 2017. The exclusion criteria were medical or neurological disorders or IQ under 70. Detected CNVs were analyzed according to the standards and guidelines of the American College of Medical Genetics. Result: Molecular karyotyping showed CNVs in four patients with EOS (encompassing the PAK2, ADAMTS3, and ADAMTSL1 genes, and the 16p11.2 microduplication syndrome) and in two patients with EOB (encompassing the ARHGAP11B and PRODH genes). In one patient with EOB, a chromosomal aneuploidy 47, XYY was found. Discussion: Our study is the first study of CNVs in EOS and EOB patients in Slovenia. Our findings support the association of the PAK2, ARHGAP11B, and PRODH genes with schizophrenia and/or bipolar disorder. To our knowledge, this is also the first report of a multiplication of the ADAMTSL1 gene and the smallest deletion of the PAK2 gene in a patient with EOS, and one of the few reports of the 47, XYY karyotype in a patient with EOB.