Early developmental impact of sex chromosome trisomies on attention deficit-hyperactivity disorder symptomology in young children.

Individuals with sex chromosome trisomies ([SCT], XXX, XXY, and XYY)) are at increased risk for neurodevelopmental problems, given that a significant portion of the sex chromosome genes impact brain functioning. An elevated risk for psychopathology has also been described, including attention deficit-hyperactivity disorder (ADHD). The present study aimed at identifying early markers of ADHD, providing the first investigation of ADHD symptomology in very young children with SCT. The variety, type, and severity of ADHD symptomology in 1-6-year-old children with SCT (n = 104) were compared with population-based controls (n = 101) using the strengths and weaknesses of ADHD symptoms and normal-behavior (SWAN) parent-report questionnaire. ADHD symptomology was significantly more prevalent in SCT and already present from toddlerhood on, compared to controls. ADHD inattention symptoms were significantly increased in all karyotypes (XXX, XXY, and XYY), boys with XYY also showed significantly more hyperactivity/impulsivity symptoms than controls. Inattentiveness was more pronounced with increasing age for SCT, in contrast to controls. Within the SCT group, 24% of the children had significantly elevated ADHD symptoms at a clinical level. Already from an early age on, SCT is associated with a risk for ADHD, suggesting that its neurodevelopmental risk lies anchored in early brain maturation. Studying this genetically vulnerable population allows for the prospective study of risk markers to facilitate early and preventive interventions.

DNA methylation and behavioral dysfunction in males with 47,XXY and 49,XXXXY: a pilot study.

BACKGROUND: Equal dosage of X-linked genes between males and females is maintained by the X-inactivation of the second X chromosome in females through epigenetic mechanisms. Boys with aneuploidy of the X chromosome exhibit a host of symptoms such as low fertility, musculoskeletal anomalies, and cognitive and behavioral deficits that are presumed to be caused by the abnormal dosage of these genes. The objective of this pilot study is to assess the relationship between CpG methylation, an epigenetic modification, at several genes on the X chromosome and behavioral dysfunction in boys with supernumerary X chromosomes. RESULTS: Two parental questionnaires, the Behavior Rating Inventory of Executive Function (BRIEF) and Child Behavior Checklist (CBCL), were analyzed, and they showed expected differences in both internal and external behaviors between neurotypical (46,XY) boys and boys with 49,XXXXY. There were several CpGs in AR and MAOA of boys with 49,XXXXY whose methylation levels were skewed from levels predicted from having one active (Xa) and three inactive (Xi) X chromosomes. Further, methylation levels of multiple CpGs in MAOA showed nominally significant association with externalizing behavior on the CBCL, and the methylation level of one CpG in AR showed nominally significant association with the BRIEF Regulation Index. CONCLUSIONS: Boys with 49,XXXXY displayed higher levels of CpG methylation at regulatory intronic regions in X-linked genes encoding the androgen receptor (AR) and monoamine oxidase A (MAOA), compared to that in boys with 47,XXY and neurotypical boys. Our pilot study results suggest a link between CpG methylation levels and behavior in boys with 49,XXXXY.

MEIS2 sequence variant in a child with intellectual disability and cardiac defects: Expansion of the phenotypic spectrum and documentation of low-level mosaicism in an unaffected parent.

Deletions and pathogenic sequence variants in Myeloid Ecotropic Insertion Site 2 (MEIS2) gene have been reported to cause a recognizable triad of intellectual disability, congenital heart malformations, and palatal defects. To date, 18 individuals with de novo pathogenic sequence variants in MEIS2 have been reported in the literature, most with all three cardinal features. We recently saw a young boy, almost 3 years of age, who was known to have mosaic XYY syndrome (47,XYY [23]/46,XY[7]). He presented with atrial and ventricular septal defects, developmental delay, facial dysmorphism, gastroesophageal reflux, undescended testicle, a buried penis with penoscrotal transposition, primary neutropenia, and a branchial cleft sinus. Whole-exome sequencing identified a previously reported in-frame pathogenic deletion (c.998_1000delGAA; p.R333del; NM_170674.4) in MEIS2. His unaffected father was confirmed to have low-level mosaicism for the same MEIS2 variant. The proband represents the 19th reported individual with a pathogenic sequence variant in MEIS2 and expands the phenotypic spectrum to include primary neutropenia, branchial anomalies, and complex genital anomalies. Furthermore, to our knowledge this is the first reported case of mosaicism for a variant in this gene in an apparently unaffected parent. This finding would have implications for recurrence risk counseling for families.

Usefulness of methylation-specific multiplex ligation-dependent probe amplification for identification of parental origin of triploidy.

Triploidy is a genetic aberration resulting from an extra haploid set of chromosomes of paternal (diandric) or maternal (digynic) origin. Diandric cases, opposite to digynic ones, may lead to gestational trophoblastic neoplasia (GTN) or generate maternal complications, therefore their identification is crucial, but reproducibility of traditionally used histopathological assessment is poor. The aim of the study was to analyse the usefulness of methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) with probes for two differentially methylated regions (DMR) at chromosome 11p.15.5 for identification of the parental origin of triploidy. 84 triploid DNA samples were tested with MS-MLPA: 34 paternal cases (40.5%) and 50 maternal ones (59.5%) according to the reference results of QF-PCR. Methylation ratio (MR) was calculated. Reference values proposed by the MRC-Holland for diploid samples (MR 0.8-1.2) were used. The values outside these ranges were used to diagnose parental origin of triploidy-paternal (MR > 1.2) or maternal (MR < 0.8). The effectiveness of MS-MLPA was 94.0%. The mean MR in paternal triploidy was 1.7 (SD-0.25; n = 34) compared with 0.56 in maternal triploidy (SD-0.12; n = 50). MR values in paternal and maternal triploidy did not overlap. In five samples (6.0%) parental origin of triploidy could not be accurately established by MS-MLPA, probably due to the maternal cell contamination (MCC). MS-MLPA can be used as a convenient method for distinguishing between paternal and maternal triploidy without the necessity for parental samples testing. It enables adequate selection of the paternal triploid cases for follow up in order to exclude post-molar GTN.

The epidemiology of sex chromosome abnormalities.

Sex chromosome abnormalities (SCAs) are characterized by gain or loss of entire sex chromosomes or parts of sex chromosomes with the best-known syndromes being Turner syndrome, Klinefelter syndrome, 47,XXX syndrome, and 47,XYY syndrome. Since these syndromes were first described more than 60 years ago, several papers have reported on diseases and health related problems, neurocognitive deficits, and social challenges among affected persons. However, the generally increased comorbidity burden with specific comorbidity patterns within and across syndromes as well as early death of affected persons was not recognized until the last couple of decades, where population-based epidemiological studies were undertaken. Moreover, these epidemiological studies provided knowledge of an association between SCAs and a negatively reduced socioeconomic status in terms of education, income, retirement, cohabitation with a partner and parenthood. This review is on the aspects of epidemiology in Turner, Klinefelter, 47,XXX and 47,XYY syndrome.

Testicular function in boys with 47,XYY and relationship to phenotype.

An additional Y chromosome occurs in ~1 in 1,000 males, resulting in the karyotype 47,XYY. The phenotype includes tall stature, hypotonia, neuropsychiatric comorbidities, and an increased risk of infertility in adulthood. Little is known about testicular function in childhood and adolescence in 47,XYY. This cross-sectional study aimed to assess testicular function serum biomarkers, including total testosterone, inhibin B, and anti-mullerian hormone (AMH), in 82 boys with XYY (11.3 ± 3.8 years) compared with 66 male controls (11.6 ± 3.8 years). The association of testicular hormones with physical features, neuropsychological phenotype, and magnetoencephalography (MEG) was assessed with multiple linear regression models. Results indicate males with XYY have significantly lower inhibin B (median 84 pg/ml vs. 109 pg/ml, p = .004) and higher AMH (median 41 ng/ml vs. 29 ng/ml, p = .011); however, testosterone, testicular volume, and stretched penile length were not different from controls. In the exploratory analysis of relationships between hormone concentrations and phenotypic assessments, higher inhibin B concentrations were positively correlated with lower BMI and better cognitive, academic, and behavioral outcomes in the XYY group. Testosterone concentrations were positively associated with better behavioral outcomes in boys with XYY. Higher testosterone and inhibin B concentrations were also associated with shorter auditory latencies measured using magnetoencephalography (MEG) in XYY. With a few exceptions, testicular hormones were not associated with phenotypic outcomes in controls. In conclusion, there is evidence of subtle impaired testicular function in boys with XYY and a newly described relationship between measures of testicular function and some aspects of the XYY phenotype.

Gonadal dysfunction and beyond: Clinical challenges in children, adolescents, and adults with 47,XXY Klinefelter syndrome.

Klinefelter syndrome (KS) is the most frequent sex chromosomal aneuploidy. The karyotype 47,XXY originates from either paternal or maternal meiotic nondisjunction during gametogenesis. KS males are very likely to exhibit marked gonadal dysfunctions, presenting both in severely attenuated spermatogenesis as well as hypergonadotropic hypogonadism. In addition, neurocognitive and psychosocial impairments, as well as cardiovascular, metabolic and bone disorders are often found in KS and might explain for an increased morbidity/mortality. All conditions in KS are likely to be induced by both gene overdosage effects resulting from supernumerary X-chromosomal genes as well as testosterone deficiency. Notwithstanding, the clinical features are highly variable between KS men. Symptoms can become obvious at infancy, childhood, or adolescence. However, the majority of KS subjects is diagnosed during adulthood. KS adolescents require specific attention regarding pubertal development, in order to exploit their remaining fertility potential and allow for timely and tailored testosterone replacement. The chances for sperm retrieval might decline with age and could be hampered by testosterone replacement; therefore, cryostorage of spermatozoa is an option during adolescence, before the decompensation of endocrine and exocrine testicular functions becomes more overt. Sperm from semen or surgically retrieved, in combination with intracytoplasmic sperm injection enables KS males to become biological fathers of healthy children. The aim of this article is to present the current knowledge on KS, to guide clinical care and to highlight research needs.

The behavioral profile of children aged 1-5 years with sex chromosome trisomy (47,XXX, 47,XXY, 47,XYY).

Children with SCT have an increased risk of suboptimal neurodevelopment. Previous studies have shown an elevated risk for neurobehavioral problems in individuals with SCT. However, not much is known about neurobehavioral problems in very young children; knowledge that could help with early identification of children at risk for suboptimal development, and that could help establish targets for early intervention. This study addressed the question of what the behavioral profile of children with SCT aged 1-5 years looks like. In total, 182 children aged 1-5 years participated in this study (NSCT =87, Nnonclinical controls = 95). Recruitment and assessment took place in the Netherlands and the United States. The SCT group was recruited through prospective follow-up (50%), information seeking parents (31%), and clinical referral (18%). Behavioral profiles were assessed with the child behavior checklist and the ages-and-stages social-emotional questionnaire. Levels of parent-rated problem behavior were higher in children with SCT. Difficulties with overall social-emotional functioning were already present in 1-year-olds, and elevated scores were persistent across the full age range. Affective and pervasive developmental behaviors were seen in late toddlerhood and prominent at preschool age. Anxiety, attention deficit, and oppositional defiant behaviors were seen in preschool-aged children. Within this cross-sectional study, the developmental trajectory of affective, pervasive developmental, and oppositional defiant behaviors seemed to be different for SCT children than nonclinical controls. Collectively, these results demonstrate the importance of behavioral screening for behavioral problems in routine clinical care for children with SCT from a young age. Social-emotional problems may require special attention, as these problems seem most prominent, showing increased risk across the full age range, and with these problems occurring regardless of the timing of diagnosis, and across all three SCT karyotypes.

Meiotic Behavior of Extra Sex Chromosomes in Patients with the 47,XXY and 47,XYY Karyotype and Its Ultimate Consequences for Spermatogenesis.

Infertility is one of the most important and burning issues in present times, as a marked increase in the frequency of infertile cases has been observed all over the world. Chromosomal aneuploidy is among the known factors associated with infertility, and among sex chromosome aneuploidies, 47,XXY and 47,XYY constitute the most common class of chromosome abnormality in human live births. Considerable attention has been given to the somatic abnormalities associated with these conditions, but less is known about their meiotic progression; that is, how sex chromosome imbalance influences the meiotic process. It has been documented that men with the same underlying genetic cause of infertility do not present with uniform pathology, so it is informative to find out how meiotic progression differs in patients with similar chromosomal aneuploidy having different phenotypes. The importance of studying meiotic progression in patients with sex chromosome abnormalities has increased many fold with the introduction of assisted reproductive technologies that have made it possible for infertile men to become biological parents. Hence, exploring the possible consequences of sex chromosome aneuploidy for meiotic chromosome segregation is worthwhile. The objective of this review, in the context of current knowledge, is to discuss problems associated with fertility and progression of meiosis in two relatively common sex chromosome aneuploidies, 47,XXY and 47,XYY, reported in humans.

Copy number variation burden does not predict severity of neurodevelopmental phenotype in children with a sex chromosome trisomy.

Sex chromosome trisomies (SCTs) (XXX, XXY, and XYY karyotypes) are associated with an elevated risk of neurodevelopmental disorders. The range of severity of the phenotype is substantial. We considered whether this variable outcome was related to the presence of copy number variants (CNVs)-stretches of duplicated or deleted DNA. A sample of 125 children with an SCT were compared with 181 children of normal karyotype who had been given the same assessments. First, we compared the groups on measures of overall CNV burden: number of CNVs, total span of CNVs, and likely functional impact (probability of loss-of-function intolerance, pLI, summed over CNVs). Differences between groups were small relative to within-group variance and not statistically significant on overall test. Next, we considered whether a measure of general neurodevelopmental impairment was predicted by pLI summed score, SCT versus comparison group, or the interaction between them. There was a substantial effect of SCT/comparison status but the pLI score was not predictive of outcomes in either group. We conclude that variable presence of CNVs is not a likely explanation for the wide phenotypic variation in children with SCTs. We discuss methodological challenges of testing whether CNVs are implicated in causing neurodevelopmental problems.

Clinical experience regarding the accuracy of NIPT in the detection of sex chromosome abnormality.

BACKGROUND: The present study aimed to determine the accuracy (Z-value) of non-invasive prenatal testing (NIPT) results for sex chromosome aneuploidy (SCA) in routine clinical practice. METHODS: Among a cohort of 12505 pregnant females, maternal plasma samples collected from our hospital were utilized for SCA analysis by NIPT detection. The positive samples were validated through an invasive procedure and karyotyping analysis. The predictive value from positive samples in sex chromosomes was compared to analyze the accuracy of the Z-value. RESULTS: There were 65 females with sex chromosome abnormalities within 12,505 pregnant females in the NIPT detection, which was validated by karyotype analysis of amniotic fluid puncture through sequencing, as well as bioinformatics analysis, with 18 true-positive samples. The true-positive results with 45,X, 47,XXY, 47,XXX and 47,XYY karyotypes predicted by NIPT were 14.29%, 50.00%, 66.67% and 71.43%, respectively. Among sex chromosome cases, the findings indicated that positive NIPT results with Z ≥ 9 show a higher accuracy. CONCLUSIONS: The findings of the present study demonstrate that the positive predictive value of NIPT for sex chromosome abnormalities is distinctive. The positive predictive value was highest for 47,XYY and lowest for 45,X. Additionally, the Z-value results are considered to be correlated with the accuracy of NIPT, although further studies need to be made.

A patient with 46,XY/47,XYY karyotype and female phenotype: a case report.

BACKGROUND: 47,XYY is a chromosomal abnormality syndrome that is typically observed in patients with a male phenotype. Few patients with XYY syndrome will have infertility. We here report a case of 46,XY/47,XYY syndrome diagnosed in a patient with a female phenotype. CASE PRESENTATION: A 15-year-old patient with a female phenotype visited our hospital owing to a chief complaint of short stature as of the age of 6 years. She was diagnosed with dwarf syndrome at the age of 10, but no change was noted after 2 months of growth hormone treatment. The patient's height was 136 cm and the weight was 29 kg, both of which were below the third percentile for her age/gender. In addition to short stature, the 4th and 5th metacarpals were short and there was no significant sex development. Karyotype analysis showed 47,XYY, and chromosomal microarray examination showed a chimera of 46,XY/47,XYY. CONCLUSION: This is an extremely rare case of 47,XYY abnormality in a patient with a female phenotype, with only one such known case reported previously. Since the cause is unknown, and symptoms of this syndrome are highly atypical and variable in childhood, clinicians should be aware of this possibility to avoid misdiagnosis and offer counseling and hormone therapy as needed to patients and their parents to improve their quality of life.

Neurodevelopmental outcome of prenatally diagnosed boys with 47,XXY (Klinefelter syndrome) and the potential influence of early hormonal therapy.

This cross-sectional study examined the neurodevelopment of a large, prenatally diagnosed population of boys with 47,XXY; investigated the potentially positive effects of early hormonal therapy (EHT) on language, cognition, and motor in this population; and identified novel at risk biomarkers associated with 47,XXY. Two-hundred and seventy two evaluations were collected from 148 prenatally diagnosed boys with 47,XXY between 0 and 36 months and separated into one of three groups, depending on visit age: Y1 (0-12 months; n = 100), Y2 (13-24 months; n = 90), and Y3 (25-36 months; n = 82). Those who received EHT (administered by 12 months) were further separated (Y1, n = 37; Y2, n = 34; Y3, n = 30). Neurodevelopmental evaluations consisted of Preschool Language Scales, Early Language Milestone Scale, and Bayley Scales of Infant and Toddler Development and evaluated the effect of EHT on auditory comprehension, expressive communication, receptive language, cognition, and motor. EHT was found to be associated with a positive effect within the first year of life in these domains, as well as in the second and third year of life. Additionally, three novel at-risk biomarkers were identified in this cohort: feeding difficulties in infancy, positional torticollis, and the need for orthotics. The positive effects of EHT observed in language, cognition, and motor at variable stages within the first 3 years of life provide additional evidence into the possible efficacy of early biological treatment for boys with 47,XXY to address the neurodevelopmental dysfunction.

Quantifying the polygenic contribution to variable expressivity in eleven rare genetic disorders.

Rare genetic disorders (RGDs) often exhibit significant clinical variability among affected individuals, a disease characteristic termed variable expressivity. Recently, the aggregate effect of common variation, quantified as polygenic scores (PGSs), has emerged as an effective tool for predictions of disease risk and trait variation in the general population. Here, we measure the effect of PGSs on 11 RGDs including four sex-chromosome aneuploidies (47,XXX; 47,XXY; 47,XYY; 45,X) that affect height; two copy-number variant (CNV) disorders (16p11.2 deletions and duplications) and a Mendelian disease (melanocortin 4 receptor deficiency (MC4R)) that affect BMI; and two Mendelian diseases affecting cholesterol: familial hypercholesterolemia (FH; LDLR and APOB) and familial hypobetalipoproteinemia (FHBL; PCSK9 and APOB). Our results demonstrate that common, polygenic factors of relevant complex traits frequently contribute to variable expressivity of RGDs and that PGSs may be a useful metric for predicting clinical severity in affected individuals and for risk stratification.

Y chromosome gene copy number and lack of autism phenotype in a male with an isodicentric Y chromosome and absent NLGN4Y expression.

We describe a unique male with a dicentric Y chromosome whose phenotype was compared to that of males with 47,XYY (XYY). The male Y-chromosome aneuploidy XYY is associated with physical, behavioral/cognitive phenotypes, and autism spectrum disorders. We hypothesize that increased risk for these phenotypes is caused by increased copy number/overexpression of Y-encoded genes. Specifically, an extra copy of the neuroligin gene NLGN4Y might elevate the risk of autism in boys with XYY. We present a unique male with the karyotype 46,X,idic(Y)(q11.22), which includes duplication of the Y short arm and proximal long arm and deletion of the distal long arm, evaluated his physical, behavioral/cognitive, and neuroimaging/magnetoencephalography (MEG) phenotypes, and measured blood RNA expression of Y genes. The proband had tall stature and cognitive function within the typical range, without autism features. His blood RNA showed twofold increase in expression of Yp genes versus XY controls, and absent expression of deleted Yq genes, including NLGN4Y. The M100 latencies were similar to findings in typically developing males. In summary, the proband had overexpression of a subset of Yp genes, absent NLGN4Y expression, without ASD findings or XYY-MEG latency findings. These results are consistent with a role for NLGN4Y overexpression in the etiology of behavioral phenotypes associated with XYY. Further investigation of NLGN4Y as an ASD risk gene in XYY is warranted. The genotype and phenotype(s) of this subject may also provide insight into how Y chromosome genes contribute to normal male development and the male predominance in ASD.

Changes in the cohort composition of turner syndrome and severe non-diagnosis of Klinefelter, 47,XXX and 47,XYY syndrome: a nationwide cohort study.

BACKGROUND: Knowledge on the prevalence of sex chromosome abnormalities (SCAs) is limited, and delayed diagnosis or non-diagnosis of SCAs are a continuous concern. We aimed to investigate change over time in incidence, prevalence and age at diagnosis among Turner syndrome (TS), Klinefelter syndrome (KS), Triple X syndrome (Triple X) and Double Y syndrome (Double Y). METHODS: This study is a nationwide cohort study in a public health care system. The Danish Cytogenetic Central Registry (DCCR) holds information on all karyotypes performed in Denmark since 1961. We identified all individuals in the DCCR with a relevant SCA during 1961-2014; TS: n = 1156; KS: n = 1235; Triple X: n = 197; and Double Y: n = 287. From Statistics Denmark, which holds an extensive collection of data on the Danish population, complete data concerning dates of death and migrations in and out of Denmark were retrieved for all individuals. RESULTS: The prevalence among newborns was as follows: TS: 59 per 100,000 females; KS: 57 per 100,000 males; Triple X: 11 per 100,000 females; and Double Y: 18 per 100,000 males. Compared with the expected number among newborns, all TS, 38% of KS, 13% of Triple X, and 18% of Double Y did eventually receive a diagnosis. The incidence of TS with other karyotypes than 45,X (P < 0.0001), KS (P = 0.02), and Double Y (P = 0.03) increased during the study period whereas the incidence of 45,X TS decreased (P = 0.0006). The incidence of Triple X was stable (P = 0.22). CONCLUSIONS: The prevalence of TS is higher than previously identified, and the karyotypic composition of the TS population is changing. Non-diagnosis is extensive among KS, Triple X and Double Y, whereas all TS seem to become diagnosed. The diagnostic activity has increased among TS with other karyotypes than 45,X as well as among KS and Double Y.

Selective advantage of euploid spermatocytes I in an azoospermic 47,XYY man with gonadal mosaicism.

Although most XYY men have normal sperm counts and are fertile (supposedly due to the loss of the extra Y before meiosis), there is a minority who are infertile. In these cases, the XYY spermatocytes are able to enter meiosis and form different synaptic configurations. With regard to mosaics, there is scarce well-defined information on the presence of the second Y and its meiotic behaviour. In this study, the chromosome constitution and the synaptic behaviour of pachytene spermatocytes from an azoospermic man with testicular hypotrophy and non-mosaic 47,XYY karyotype were analysed. Furthermore, we determined the chromosome constitution of the somatic Sertoli cells. Five karyotypically normal men with obstructive azoospermia, but having complete spermatogenesis, were included as controls. Immuno-FISH using specific protein markers of synapsis and recombination (SYCP3, SYCP1, BRCA1, MLH1, CREST) and a specific Yq12 DNA probe were used. In addition, we used the newly developed Super-Resolution Structured Illumination Microscopy (SR-SIM) to clearly define the synaptic configurations. FISH analysis was also performed on Sertoli cells. The histopathological analysis showed variable degrees of spermatogenesis development in the testicular tissue of the propositus. Immuno-FISH analysis showed that most of the primary spermatocytes were euploid 46, XY. The use of SR-SIM confirmed the existence of this euploidy. Only a few pachytene spermatocytes showed an aneuploid X + YY constitution. Sertoli cells showed two different populations with one or two Y chromosomes, in similar proportions. Thus an abnormal niche of sex-trisomic Sertoli cells should be also considered when searching for the origin of spermatogenesis failure in XYY men.

Sex differences in psychiatric disorders: what we can learn from sex chromosome aneuploidies.

The study of sexual dimorphism in psychiatric and neurodevelopmental disorders is challenging due to the complex interplay of diverse biological, psychological, and social factors. Males are more susceptible to neurodevelopmental disorders including intellectual disability, autism spectrum disorder, and attention-deficit activity disorder. Conversely, after puberty, females are more prone to major depressive disorder and anxiety disorders compared to males. One major biological factor contributing to sex differences is the sex chromosomes. First, the X and Y chromosomes have unique and specific genetic effects as well as downstream gonadal effects. Second, males have one X chromosome and one Y chromosome, while females have two X chromosomes. Thus, sex chromosome constitution also differs between the sexes. Due to this complexity, determining genetic and downstream biological influences on sexual dimorphism in humans is challenging. Sex chromosome aneuploidies, such as Turner syndrome (X0) and Klinefelter syndrome (XXY), are common genetic conditions in humans. The study of individuals with sex chromosome aneuploidies provides a promising framework for studying sexual dimorphism in neurodevelopmental and psychiatric disorders. Here we will review and contrast four syndromes caused by variation in the number of sex chromosomes: Turner syndrome, Klinefelter syndrome, XYY syndrome, and XXX syndrome. Overall we describe an increased rate of attention-deficit hyperactivity disorder and autism spectrum disorder, along with the increased rates of major depressive disorder and anxiety disorders in one or more of these conditions. In addition to contributing unique insights about sexual dimorphism in neuropsychiatric disorders, awareness of the increased risk of neurodevelopmental and psychiatric disorders in sex chromosome aneuploidies can inform appropriate management of these common genetic disorders.

Outcomes of Preimplantation Genetic Diagnosis Cycles by Fluorescent In situ Hybridization of Infertile Males with Nonmosaic 47,XYY Syndrome.

BACKGROUND: The 47,XYY syndrome could result in fertility problems. However, seldom studies reported comprehensive researches on the embryonic development and pregnancy outcomes of these patients. This study aimed to evaluate the clinical outcomes of nonmosaic 47,XYY patients performed with fluorescent in situ hybridization (FISH) and preimplantation genetic diagnosis (PGD) treatment. METHODS: This was a retrospective study. Between January 2012 and May 2017, 51 infertile males with nonmosaic 47,XYY syndrome underwent FISH-PGD were included in the study. According to sex chromosomal FISH results, embryos were classified as normal signal, no nuclei fixed, no signal in fixed nuclei, suspensive signal, and abnormal signal groups, respectively. The incidence of each group, the fixation rate, and hybridization rate were calculated. Embryonic development and pregnancy outcomes were also analyzed. The measurement data were analyzed with Student's t-test. The comparison of categorical data was analyzed with the Chi-square test and Fisher's exact test when expected cell count was <5. RESULTS: The 53 PGD cycles with 433 embryos were analyzed. The fixation rate was 89.6%, while the hybridization rate was 96.4%. There were 283 embryos with two sex chromosomal signals with clear diagnosis (65.4%). The numbers of no nuclei fixed, no signal in fixed nuclei, suspensive signal, and abnormal signal groups were 45 (10.4%), 14 (3.2%), 24 (5.5%), and 67 (15.5%), respectively. Embryos with abnormal signals were abandoned. The number of good-quality embryos was 210 (57.4%), including implanted embryos on day 4/day 5 and cryopreserved. The rates of good-quality embryos in the no nuclei fixed (22.2%), no signal in fixed nuclei (28.6%), and suspensive signal groups (33.3%) were comparable (P > 0.05), and were significantly lower than the normal signal group (66.4%, P < 0.001). The clinical pregnancy rates of fresh and frozen embryos transferred cycles were 70.6% and 85.7%, respectively. CONCLUSIONS: Among embryos with a clear diagnosis of sex chromosome, about one-fifth showed abnormal signals. Embryos with two sex chromosomal signals are more likely to develop into good-quality ones. The application of the PGD by FISH may help to improve the clinical outcome s.