48,XXYY, 48,XXXY and 49,XXXXY syndromes: not just variants of Klinefelter syndrome

A pseudoautosomal glycosylation disorder prompts the revision of dolichol biosynthesis

Dolichol is a lipid critical for N-glycosylation as a carrier for activated sugars and nascent oligosaccharides. It is commonly thought to be directly produced from polyprenol by the enzyme SRD5A3. Instead, we found that dolichol synthesis requires a three-step detour involving additional metabolites, where SRD5A3 catalyzes only the second reaction. The first and third steps are performed by DHRSX, whose gene resides on the pseudoautosomal regions of the X and Y chromosomes. Accordingly, we report a pseudoautosomal-recessive disease presenting as a congenital disorder of glycosylation in patients with missense variants in DHRSX (DHRSX-CDG). Of note, DHRSX has a unique dual substrate and cofactor specificity, allowing it to act as a NAD+-dependent dehydrogenase and as a NADPH-dependent reductase in two non-consecutive steps. Thus, our work reveals unexpected complexity in the terminal steps of dolichol biosynthesis. Furthermore, we provide insights into the mechanism by which dolichol metabolism defects contribute to disease.

Discordant Prenatal Cell-Free DNA Screening vs. Diagnostic Results of Sex Chromosome Aneuploidies: Implications for Newborn Screening and Genetic Counseling

Sex chromosome aneuploidies (SCAs) collectively occur in 1 in 500 livebirths, and diagnoses in the neonatal period are increasing with advancements in prenatal and early genetic testing. Inevitably, SCA will be identified on either routine prenatal or newborn screening in the near future. Tetrasomy SCAs are rare, manifesting more significant phenotypes compared to trisomies. Prenatal cell-free DNA (cfDNA) screening has been demonstrated to have relatively poor positive predictive values (PPV) in SCAs, directing genetic counseling discussions towards false-positive likelihood rather than thoroughly addressing all possible outcomes and phenotypes, respectively. The eXtraordinarY Babies study is a natural history study of children prenatally identified with SCAs, and it developed a longitudinal data resource and common data elements with the Newborn Screening Translational Research Network (NBSTRN). A review of cfDNA and diagnostic reports from participants identified a higher than anticipated rate of discordance. The aims of this project are to (1) compare our findings to outcomes from a regional clinical cytogenetic laboratory and (2) describe discordant outcomes from both samples. Twenty-one (10%), and seven (8.3%) cases were found to be discordant between cfDNA (result or indication reported to lab) and diagnosis for the Babies Study and regional laboratory, respectively. Discordant results represented six distinct discordance categories when comparing cfDNA to diagnostic results, with the largest groups being Trisomy cfDNA vs. Tetrasomy diagnosis (66.7% of discordance in eXtraordinarY Babies study) and Mosaicism (57.1% in regional laboratory). Traditional genetic counseling for SCA-related cfDNA results is inadequate given a high degree of discordance that jeopardizes the accuracy of the information discussed and informed decision making following prenatal genetic counseling.

Foveal hypoplasia in a Chinese adolescent with 48, XXYY syndrome

BACKGROUND

48, XXYY syndrome is a rare sex chromosome aneuploidy with severe systemic features. Ophthalmic manifestation of 48, XXYY syndrome include hypertelorism, epicanthic folds, hooded eye lids, strabismus, retinitis pigmentosa and Duane's syndrome.

CASE

We present mild foveal hypoplasia in a 12-year-old boy with 48, XXYY syndrome using swept-source optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). The boy was referred for assessment of strabismus and poor visual acuity. OCT revealed persistence of inner retinal layers, and thinning of the outer nuclear layer in the perifoveal region with thickening of the outer plexiform layer. OCTA revealed increased vessel density with reduced foveal avascular zone.

CONCLUSION

We described novel OCT and OCTA features of bilateral foveal hypoplasia and reduction of FAZ in a case of 48, XXYY syndrome based on detailed clinical observation and thorough genetic testing. This case expanded the current literature of this rare sex chromosome abnormality and suggest the importance of retinal examinations in 48, XXYY syndrome.

Giftedness and atypical sexual differentiation: enhanced perceptual functioning through estrogen deficiency instead of androgen excess

Syndromic autism spectrum conditions (ASC), such as Klinefelter syndrome, also manifest hypogonadism. Compared to the popular Extreme Male Brain theory, the Enhanced Perceptual Functioning model explains the connection between ASC, savant traits, and giftedness more seamlessly, and their co-emergence with atypical sexual differentiation. Overexcitability of primary sensory inputs generates a relative enhancement of local to global processing of stimuli, hindering the abstraction of communication signals, in contrast to the extraordinary local information processing skills in some individuals. Weaker inhibitory function through gamma-aminobutyric acid type A (GABAA) receptors and the atypicality of synapse formation lead to this difference, and the formation of unique neural circuits that process external information. Additionally, deficiency in monitoring inner sensory information leads to alexithymia (inability to distinguish one's own emotions), which can be caused by hypoactivity of estrogen and oxytocin in the interoceptive neural circuits, comprising the anterior insular and cingulate gyri. These areas are also part of the Salience Network, which switches between the Central Executive Network for external tasks and the Default Mode Network for self-referential mind wandering. Exploring the possibility that estrogen deficiency since early development interrupts GABA shift, causing sensory processing atypicality, it helps to evaluate the co-occurrence of ASC with attention deficit hyperactivity disorder, dyslexia, and schizophrenia based on phenotypic and physiological bases. It also provides clues for understanding the common underpinnings of these neurodevelopmental disorders and gifted populations.

Evidence-based recommendations for delivering the diagnosis of X & Y chromosome multisomies in children, adolescents, and young adults: an integrative review

BACKGROUND

The diagnosis of supernumerary X & Y chromosome variations has increased following the implementation of genetic testing in pediatric practice. Empirical evidence suggests that the delivery of the diagnosis has a lasting impact on how affected individuals and their parents perceive and adapt to the diagnosis. The purpose of this review is to synthesize the literature to obtain useful recommendations for delivering a pediatric diagnosis of a sex chromosome multisomy (SCM) based upon a growing body of quantitative and qualitative literature on patient experiences.

METHODS

We conducted an integrative literature review using PubMed, Web of Science and CINAHL employing keywords "genetic diagnosis delivery," "genetic diagnosis disclosure," "sex chromosome aneuploidy," "Klinefelter syndrome" or ""47, XXY," "Jacob syndrome" or "47, XYY," "Trisomy X," "Triple X" or "47, XXX," and "48 XXYY from January 1, 2000, to October 31, 2023.

RESULTS

Literature supports that patients and parents value the provision of up-to-date information and connection with supportive resources. Discussion of next steps of care, including relevant referrals, prevents perceptions of provider abandonment and commitment to ongoing support. Proactively addressing special concerns such as disclosing the diagnosis to their child, family, and community is also beneficial. Tables are provided for useful information resources, medical specialties that may be required to support patients, and common misconceptions that interfere with accurate information about the diagnosis.

CONCLUSION

Patient experiences suggest there should be heightened attention to diagnosis delivery, in reference to the broader ethical and social impacts of a SCM diagnosis. We present recommendations for optimal disclosure of a SCM diagnosis in early and late childhood, adolescence, and young adulthood.

A Challenging Case of Diabetes in a Patient With XXYY Syndrome

48 XXYY syndrome is a rare polyploidy often compared with Klinefelter syndrome because of shared features such as tall stature, neurocognitive diseases, hypogonadism, and cardiac malformations. This population is believed to be predisposed to type 2 diabetes because of the presence of hypogonadism and central adiposity. We present a patient with XXYY syndrome who had an atypical and difficult-to-manage diabetes presentation. The patient was nonadherent to medication regimen with poorly controlled diabetes and hemoglobin A1c ranging from 12% to 14% (16.5-19.6 mmol/L). He lacked history of diabetes ketoacidosis, raising the question of maturity-onset diabetes of the young. Workup was negative for glutamic acid decarboxylase-65 and pancreatic islet cell antibody testing. Genetic testing for 5-gene panel for maturity-onset diabetes of the young was also negative. Distinct parts of his presentation make an accurate diabetes diagnosis very challenging. Clinicians should be aware of diabetes associations in patients with XXYY syndrome for optimization of care.

Healthcare and support experiences of adolescents and young adults diagnosed with 47,XXY, 47,XXX, and 48,XXYY

Sex chromosome aneuploidies (SCAs) are among the most common chromosomal conditions. There is little scholarship on how adolescents and young adults (AYAs) affected by SCA engage with and adapt to their diagnosis. In order to understand how AYAs adapt to a SCA diagnosis, we conducted a secondary analysis of qualitative interviews with AYAs. Eight in-depth semi-structured interviews with individuals with a diagnosis of 47,XXY, 47,XXX, and 48,XXYY were analyzed for iterative themes related to adaptation to a SCA diagnosis in accordance with standard qualitative methodology. Our findings suggest that the process of adaptation is highly variable and complex and is mediated by external factors including diagnosis delivery and community support. Factors associated with adaptation include feeling understood and supported by healthcare providers; researching the condition; receiving hormone replacement therapy; and receiving support from a community of peers. As access to prenatal and pediatric genetic testing continues to expand, non-genetic pediatric providers are increasingly likely to interact with individuals with SCAs as part of their initial diagnostic odyssey or ongoing medical management. Understanding the diversity of lived experiences of AYAs with SCAs is helpful for healthcare providers to facilitate holistic care and provide meaningful support to patients.

Generation of iPSC Cell Lines from Patients with Sex Chromosome Aneuploidies

Somatic cell reprogramming allows the generation of human induced pluripotent stem cells (iPSCs) from patient's cells. The derived iPSCs provide an unlimited source of patient-specific cells that can be virtually differentiated in any cell of the human body. The generation of iPSCs has important implications for all human medicine fields, as they can be used for drug discovery, regenerative medicine, and developmental studies. Klinefelter Syndrome (KS) is the most common chromosome aneuploidy in males. KS is typically characterized by a 47,XXY karyotype, representing 80-90% of KS patients. In rare cases, high-grade sex chromosome aneuploidies (SCAs), 48,XXXY; 48,XXYY; 49,XXXXY, are also observed in males. Since the advent of the reprogramming technique, a few KS-iPSCs have been described. Here, we detail the methodology for generating primary fibroblasts from patients' skin biopsies and the subsequent derivation of iPSCs using an efficient integrative-free mRNA-based somatic reprogramming approach.

Dermatologic care of patients with differences of sex development

Background

Differences of sex development (DSD or disorders of sex development) are uncommon congenital conditions, characterized by atypical development of chromosomal, gonadal, or anatomic sex.

Objective

Dermatologic care is an important component of the multidisciplinary care needed for individuals with DSD. This article discusses the most common primary dermatologic manifestations of DSD in addition to the cutaneous manifestations of hormonal and surgical therapies in individuals with DSD.

Data sources

Published articles including case series and case reports on PubMed.

Study selections

Selection was conducted by examining existing literature with a team of multidisciplinary specialists.

Methods

Narrative review.

Limitations

This article was not conducted as a systematic review.

Results

In Klinefelter syndrome, refractory leg ulcers and incontinentia pigmenti have been described. Turner syndrome is associated with lymphatic malformations, halo nevi, dermatitis, and psoriasis. Virilization can be seen in some forms of congenital adrenal hyperplasia, where acne and hirsutism are common.

Conclusion

Dermatologists should consider teratogenic risk for treatments of skin conditions in DSD depending on pregnancy potential. Testosterone replacement, commonly used for Klinefelter syndrome, androgen insensitivity syndrome, 5-alpha reductase deficiency, gonadal dysgenesis, or ovotesticular DSD, may cause acne.

"Knowledge is Power": Parent Views on the Benefits of Early Diagnosis and Awareness of Sex Chromosome Multisomy Among Pediatric Professionals

OBJECTIVE

Pediatric diagnoses of sex chromosome multisomies (SCMs) have increased as genetic testing has expanded. However, depending on SCM presentation, there may be significant delays between symptom recognition and diagnosis. We conducted a survey of parents of children diagnosed with SCMs to understand their experiences receiving an SCM diagnosis and their support needs.

METHODS

We conducted an inductive qualitative analysis of open-ended survey responses for iterative themes related to presenting symptoms, diagnostic odyssey, immediate and long-term support needs, and awareness of SCMs.

RESULTS

Of the 323 parents who completed the survey, 185 parents received a pediatric diagnosis (0-21 years) in a child. Many parents expressed feelings of relief when receiving the diagnosis, especially if it occurred after a lengthy diagnostic odyssey. Parents reported frustration that their child's nonmedical symptoms, including learning disabilities, speech delays, attention deficits, and behavioral issues, were not flagged as potential indications for SCMs and suggested that greater awareness of SCMs by pediatricians, educators, and other professionals involved in their child's care may lead to earlier diagnosis and intervention.

CONCLUSION

This is the largest qualitative study to date examining parent and caregiver experiences with a pediatric diagnosis of SCMs. Increased knowledge and awareness of nonmedical SCM symptoms are needed among medical, education, occupational, and psychology professionals for early testing referral and improved support of children with SCMs.

Noninvasive prenatal screening (NIPS) results for participants of the eXtraordinarY babies study: Screening, counseling, diagnosis, and discordance

Sex chromosome aneuploidies (SCAs), including 47,XXY, 47,XXX, 47,XYY, and supernumerary variants, occur collectively in approximately one of 500 live births. Clinical phenotypes are highly variable resulting in previous ascertainment rates estimated to be only 10%-25% during a lifetime. Historically, prenatal SCA diagnoses were incidental findings, accounting for ≤10% of cases, with the majority of diagnoses occurring postnatally during evaluations for neurodevelopmental, medical, or infertility concerns. The initiation of noninvasive prenatal screening (NIPS) in 2012 and adoption into standardized obstetric care provides a unique opportunity to significantly increase prenatal ascertainment of SCAs. However, the impact NIPS has had on ascertainment of SCAs is understudied, particularly for those who may defer diagnostic testing until after birth. This study evaluates the timing of diagnostic testing following positive NIPS in 152 infants with SCAs and potential factors influencing this decision. Eighty-seven (57%) elected to defer diagnostic testing after a positive NIPS until birth, and 8% (7/87) of those confirmed after birth were found to have discordant results on postnatal diagnostic testing, most of which would have influenced genetic counseling.

State-wide increase in prenatal diagnosis of klinefelter syndrome on amniocentesis and chorionic villus sampling: Impact of non-invasive prenatal testing for sex chromosome conditions

BACKGROUND

To analyze population-based trends in the prenatal diagnosis of sex chromosome aneuploidy (SCA) since the availability of non-invasive prenatal testing (NIPT).

METHODS

Retrospective state-wide data for all prenatal diagnoses performed <25 weeks gestation from 2005 to 2020 in Victoria, Australia. Non-invasive prenatal testing became locally available from 2012. The prenatal diagnosis rates of SCA as proportions of all prenatal diagnostic tests and all births were calculated. Statistical significance was assessed with the χ2 test for trend, with p < 0.05 considered significant.

RESULTS

46,518 amniocentesis and chorionic villus sampling were performed during the study period, detecting 617 SCAs. There was a significant increase in the rate of prenatal SCAs from 5.8 per 10,000 births in 2005 to 8.7 per 10,000 births in 2020 (p < 0.0001). This increase was predominantly due to 47,XXY cases, 91% of which were ascertained via positive NIPT for this condition in 2020. The prenatal diagnosis rate of 47,XXY significantly increased from 0.8 per 10,000 births in 2005 to 4.3 per 10,000 births in 2020 (p < 0.0001).

CONCLUSION

Screening for SCAs using NIPT has directly led to an increase in their prenatal diagnosis on a population-wide basis, especially 47,XXY. This has implications for clinician education, genetic counselling, and pediatric services.

Clinical, Cognitive and Neurodevelopmental Profile in Tetrasomies and Pentasomies: A Systematic Review

Background: Sex chromosome aneuploidies (SCAs) are a group of disorders characterised by an abnormal number of sex chromosomes. Collective prevalence rate of SCAs is estimated to be around 1 in 400-500 live births; sex chromosome trisomies (e.g., XXX, XXY, XYY) are most frequent, while tetra- and pentasomies (e.g., XXXX, XXXXX, XXXY, XXXXY) are rarer, and the most common is 48, XXYY syndrome. The presence of additional X and/or Y chromosomes is believed to cause neurodevelopmental differences, with increased risk for developmental delays, language-based learning disabilities, cognitive impairments, executive dysfunction, and behavioural and psychological disorders. Aim of the Study: Our review has the purpose of analysing the neurocognitive, linguistical and behavioural profile of patients affected by sex chromosomes supernumerary aneuploidies (tetrasomy and pentasomy) to better understand the specific areas of weakness, in order to provide specific rehabilitation therapy. Methods: The literature search was performed by two authors independently. We used MEDLINE, PubMed, and PsycINFO search engines to identify sources of interest, without year or language restrictions. At the end of an accurate selection, 16 articles fulfilled the inclusion and exclusion criteria. Results and Conclusions: International literature has described single aspects of the neuropsychological profile of 48, XXYY and 49, XXXXY patients. In 48, XXYY patients, various degrees of psychosocial/executive functioning issues have been reported and there is an increased frequency of behavioural problems in childhood. Developmental delay and behavioural problems are the most common presenting problems, even if anxiety, depression and oppositional defiant disorder are also reported. They also show generalized difficulties with socialization and communication. Cognitive abilities are lower in measures of verbal IQ than in measures of performance IQ. Visuospatial skills are a relative strength compared to verbal skills. In patients with 49, XXXXY, both intellectual and adaptive functioning skills fall into the disability range, with better non-verbal cognitive performance. Speech and language testing reveals more deficits in expressive language than receptive language and comprehension. Anxiety, thought problems, internalizing and externalizing problems, and deficits in social cognition and communication are reported. Behavioural symptoms lessen from school age to adolescence, with the exception of thought problems and anxiety. Individuals affected by sex chromosome aneuploidies show testosterone deficiency, microorchidism, lack of pubertal progression and infertility. Hormone replacement therapy (HRT) is usually recommended for these patients: different studies have found that testosterone-based HRT benefit a wide range of areas initiated in these disorders, affecting not only neuromotor, cognitive and behavioural profile but also structural anomalies of the brain (i.e., increase of volume of grey temporal lobe matter). In conclusion, further studies are needed to better understand the neuropsychological profile with a complete evaluation, including neurocognitive and psychosocial aspects and to establish the real impact of HRT on improving the cognitive and behavioural profile of these patients.

Supporting students with sex chromosome aneuploidies in educational settings: Results of a nationwide survey

Children with sex chromosome aneuploidies (SCAs) are at an increased risk for neurocognitive and behavioral disorders that may interfere with academic success, including early developmental delays, learning disabilities, executive function problems, and social communication deficits. The present national survey aimed to update and extend our understanding of school supports and educational outcomes for students with these increasingly common genetic diagnoses. Parents of children with a diagnosed SCA, birth to 21 years, living in the United States (N = 248), responded to an electronic survey with questions focused on school support plans, academic accommodations, educational therapies, school completion, and perceptions of educator awareness of SCAs. Results revealed high rates of delayed kindergarten, grade retention in primary years, and educational support plans (IEPs = 71%; Section 504 Plans = 26%). A majority (73%) of respondents with children over age 18 years (N = 41) reported their children successfully completed high school, and nearly half (46%) pursued post-secondary education opportunities. Many parents reported their children's educators had little to no knowledge of SCA conditions, justifying a need to train teachers and policy makers in the unique educational needs of children and adolescents with SCAs. School psychologists should be aware of the frequent need for accommodations and individualized support plans in this population so they can support children and families by advocating for early and comprehensive evaluations and intervention plans.

Metabolic and Nutritional Aspects in Paediatric Patients with Klinefelter Syndrome: A Narrative Review

Klinefelter syndrome is the most common sex chromosomal aneuploidy in males. It is well known that patients with this syndrome have greater mortality and morbidity compared to the general population due to cardiovascular diseases and endocrine metabolism disorders. This augmented risk is due both to hypogonadism and to the syndrome itself. Therefore, correct hormonal replacement therapy and early primary prevention are crucial to these patients. Even though different studies are available on this topic in adult patients, only a few authors have focused on the paediatric population. Thus, in this narrative review, we report the current knowledge of metabolic and nutritional aspects in children with Klinefelter syndrome.

Prevalence and patterns of chromosomal abnormalities among Egyptian patients with infertility: a single institution’s 5-year experience

Background

Chromosomal abnormalities represent an important cause of human infertility. Little is known about the prevalence of chromosomal abnormalities among Egyptian couples with infertility. We estimated the cytogenetic profiles and semen analysis patterns among infertile couples. We analyzed data from medical archives of 2150 patients with infertility in Mansoura University Children’s Hospital, Egypt from 2015 to 2019. The data included karyotypes and semen analysis reports.

Results

Chromosomal abnormalities were reported in 13.5% of infertile patients (290/2150); 150 out of 1290 (11.62%) males and 140 out of 860 (16.28%) females. Within the infertile males, the numerical chromosomal abnormalities were detected in 134/1290 (10.38%) males, and structural abnormalities were found in 16/1290 (1.24%) males. Within the infertile females, numerical sex chromosome abnormalities were detected in 75/860 (8.72%) females, structural sex chromosome abnormalities were found in 31/860 (3.6%) females, mosaicism of the sex chromosome was found in 22/860 (2.56%) females, and male pseudohermaphrodites were detected in 12/860 (1.39%) females.

Conclusions

Numerical chromosomal aberrations are the most frequent patterns among infertile couples. Attention should be paid to the traditional chromosomal analysis as an important diagnostic step in the infertility work-up.

A Patient with Moderate Intellectual Disability and 49, XXXYY Karyotype

Klinefelter syndrome is a chromosomal disorder in which one extra X chromosome is present (47,XXY). Several other numeric variants of this syndrome are described that comprise one or more additional sex chromosomes such as 48,XXXY, 48,XXYY and 49,XXXXY. These rare conditions are often associated with increased risk for congenital malformations, additional medical problems, and a more complex psychological phenotype. Since 1963, apart from two infants, only four adult patients with a XXXYY pentasomy have been published as case report. The present paper critically reviews the existing literature and provides detailed assessments of a 25-year-old male with intellectual disability and autism. For the first time, this very rare pentasomy is now recorded using all information about developmental history as well as findings from genetic, somatic, endocrinological and neuropsychological examination. It is concluded that children born with abnormalities of the external genitalia should always be evaluated for genetic abnormalities in order to avoid unwanted delay of appropriately designed multidisciplinary medical and psychological treatment.

Pseudoautosomal Region 1 Overdosage Affects the Global Transcriptome in iPSCs From Patients With Klinefelter Syndrome and High-Grade X Chromosome Aneuploidies

Klinefelter syndrome (KS) is the most prevalent aneuploidy in males and is characterized by a 47,XXY karyotype. Less frequently, higher grade sex chromosome aneuploidies (HGAs) can also occur. Here, using a paradigmatic cohort of KS and HGA induced pluripotent stem cells (iPSCs) carrying 49,XXXXY, 48,XXXY, and 47,XXY karyotypes, we identified the genes within the pseudoautosomal region 1 (PAR1) as the most susceptible to dosage-dependent transcriptional dysregulation and therefore potentially responsible for the progressively worsening phenotype in higher grade X aneuploidies. By contrast, the biallelically expressed non-PAR escape genes displayed high interclonal and interpatient variability in iPSCs and differentiated derivatives, suggesting that these genes could be associated with variable KS traits. By interrogating KS and HGA iPSCs at the single-cell resolution we showed that PAR1 and non-PAR escape genes are not only resilient to the X-inactive specific transcript (XIST)-mediated inactivation but also that their transcriptional regulation is disjointed from the absolute XIST expression level. Finally, we explored the transcriptional effects of X chromosome overdosage on autosomes and identified the nuclear respiratory factor 1 (NRF1) as a key regulator of the zinc finger protein X-linked (ZFX). Our study provides the first evidence of an X-dosage-sensitive autosomal transcription factor regulating an X-linked gene in low- and high-grade X aneuploidies.

Case report: Bipolar disorder in 48,XXYY syndrome

48,XXYY syndrome is a rare condition. The presentations of impulsive and aggressive behavior have been reported in several case reports among patients with 48,XXYY syndrome. The management of the psychological impact and neuropsychiatric sequela of this condition is a significant issue faced by families, carers, and healthcare professionals. We report a patient, 21-year-old Malay male, with underlying 48,XXYY syndrome with attention deficit hyperactivity disorder (ADHD) and intellectual disability, diagnosed later in adulthood with a bipolar mood disorder and benefited after being started on lithium. We describe the key clinical features and diagnostic workouts that allowed the arrival of the correct psychiatric diagnosis. Challenges in psychopharmacotherapy, including the risks of metabolic syndrome and deep vein thrombosis associated with 48,XXYY syndrome, are also considered. We suggest that for patients with 48,XXYY syndrome, routine psychological screening for mood symptoms such as mania and depression should be done by healthcare professionals with early involvement of psychiatrist in the multidisciplinary team due to the challenges in the management of these patients.

An infant with 49XXXXY syndrome: a case report

Background

49XXXXY syndrome is the rarest X chromosome aneuploidy, with approximate incidence of 1:85,000–100,000 male births. Worldwide, around 100 cases have been reported. In this report, we describe one such case seen in Sri Lanka.

Case presentation

A 10-day-old Sri Lankan neonate born in a tertiary care center was referred to the pediatric endocrinology unit of Lady Ridgeway Hospital due to detection of ambiguous genitalia at birth. He was the first child born to nonconsanguineous healthy parents following an uncomplicated antenatal period. He was born at term via normal vaginal delivery, with a birth weight of 2.385 kg. The baby was active, and there was no documented hypoglycemia or alteration in basic biochemical investigations. On examination, the child had hypertelorism, upslanting palpebral fissures, flat occiput, and mild webbing of the neck. System examination was normal. Genitalia examination revealed bifid scrotum, perineal urethra, 2 cm phallus, and bilateral testis in situ. Hormonal analysis, including dehydroepiandrosterone sulfate, testosterone, and 17-OH progesterone levels, was normal except for an elevated level of follicle-stimulating hormone, indicating gonadal dysgenesis. Ultrasound of the abdomen detected testis located at bilateral inguinal canal, and no Müllerian structures were visible. Echocardiography showed a small patent foramen ovale with otherwise normal heart. Chromosome analysis revealed 49XXXXY syndrome.

Conclusion

49XXXXY syndrome should be entertained as a rare possibility for ambiguous genitalia, and karyotyping is an essential investigation for evaluation of such patients.

Patterns of psychopathology and cognition in sex chromosome aneuploidy

Background

Sex chromosome aneuploidies (SCAs) are a collectively common family of genetic disorders that increase the risk for neuropsychiatric and cognitive impairment. Beyond being important medical disorders in their own right, SCAs also offer a unique naturally occurring model for studying X- and Y-chromosome influences on the human brain. However, it remains unclear if (i) different SCAs are associated with different profiles of psychopathology and (ii) the notable interindividual variation in psychopathology is related to co-occurring variation in cognitive ability.

Methods

We examined scores for 11 dimensions of psychopathology [Child/Adult Behavior Checklist (CBCL)] and general cognitive ability [full-scale IQ (FSIQ) from Wechsler tests] in 110 youth with varying SCAs (XXY = 41, XYY = 22, XXX = 27, XXYY = 20) and 131 typically developing controls (XX = 59, XY = 72).

Results

All SCAs were associated with elevated CBCL scores across several dimensions of psychopathology (two-sample t tests comparing the euploidic and aneuploidic groups [all |T| > 9, and p < 0.001]). Social and attentional functioning were particularly sensitive to the carriage of a supernumerary Y-chromosome. In particular, the XYY group evidenced significantly more social problems than both extra-X groups (Cohen’s d effect size > 0.5, Bonferroni corrected p < .05). There was marked variability in CBCL scores within each SCA group, which generally correlated negatively with IQ, but most strongly so for social and attentional difficulties (standardized β, − 0.3). These correlations showed subtle differences as a function of the SCA group and CBCL scale.

Conclusions

There is domain-specific variation in psychopathology across SCA groups and domain-specific correlation between psychopathology and IQ within SCAs. These findings (i) help to tailor clinical assessment of this common and impactful family of genetic disorders and (ii) suggest that dosage abnormalities of X- and Y-linked genes impart somewhat distinct profiles of neuropsychiatric risk.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11689-021-09407-9.

What Every Internist-Endocrinologist Should Know about Rare Genetic Syndromes in Order to Prevent Needless Diagnostics, Missed Diagnoses and Medical Complications: Five Years of 'Internal Medicine for Rare Genetic Syndromes'

Patients with complex rare genetic syndromes (CRGS) have combined medical problems affecting multiple organ systems. Pediatric multidisciplinary (MD) care has improved life expectancy, however, transfer to internal medicine is hindered by the lack of adequate MD care for adults. We have launched an MD outpatient clinic providing syndrome-specific care for adults with CRGS, which, to our knowledge, is the first one worldwide in the field of internal medicine. Between 2015 and 2020, we have treated 720 adults with over 60 syndromes. Eighty-nine percent of the syndromes were associated with endocrine problems. We describe case series of missed diagnoses and patients who had undergone extensive diagnostic testing for symptoms that could actually be explained by their syndrome. Based on our experiences and review of the literature, we provide an algorithm for the clinical approach of health problems in CRGS adults. We conclude that missed diagnoses and needless invasive tests seem common in CRGS adults. Due to the increased life expectancy, an increasing number of patients with CRGS will transfer to adult endocrinology. Internist-endocrinologists (in training) should be aware of their special needs and medical pitfalls of CRGS will help prevent the burden of unnecessary diagnostics and under- and overtreatment.

Eosinophilic esophagitis in individuals with sex chromosome aneuploidies: Clinical presentations and management implications

Background

Supernumerary sex chromosome aneuploidies (SCA) are common genetic conditions characterized by additional X or Y chromosome, affecting ~1/500 individuals, with the most frequent karyotypes of 47,XXY (Klinefelter syndrome), 47,XXX (Trisomy X), and 47,XYY (Jacob syndrome). Although there is considerable phenotypic variation among these diagnoses, these conditions are characterized by the presence of overlapping physical, medical, developmental, and psychological features. Our interdisciplinary clinic’s experience anecdotally supports previous published findings of atopic conditions, feeding difficulties, and gastroesophageal reflux to be more prevalent in SCAs (Bardsley et al., Journal of Pediatrics, 2013, 163, 1085; Samango‐Sprouse et al., The Application of Clinical Genetics, 2019, 12, 191; Tartaglia et al., Acta Paediatrica, 2008, 100, 851). Furthermore, we observed that many of these patients have also been diagnosed with eosinophilic esophagitis (EoE), an association not currently reported in the literature.

Methods

We conducted a retrospective chart review of all 667 patients with SCA seen at a large tertiary care center to investigate the prevalence and presenting features of EoE.

Results

Four percent of children with SCAs had a biopsy‐confirmed diagnosis of EoE, which represents an odds ratio of 32 (95% CI 6–185) when compared to the prevalence rates reported in the general population.

Conclusion

Routine screening for EoE symptoms may be warranted for individuals with SCA and atopic conditions.

Occurrence of Klinefelter Syndrome Mosaic 45,X/46,XY/47,XXY/48,XXYY/48,XXXY and Primary Hyperparathyroidism

Objective

The presence of primary hyperparathyroidism (PHPT) and Klinefelter syndrome (KS) is rare, and its association with KS mosaicism is even rarer. We report an unusual combination of these entities with a mild phenotype of KS.

Methods

The patient was a 44-year-old male with a history of PHPT who had recurrent urolithiasis despite being treated with a successful parathyroidectomy. On examination, he had axillary hair growth, bilateral gynecomastia, a large port-wine stain at the right hemithorax and upper right limb, and genitalia and pubic hair corresponding to Tanner IV classification with small, normal consistency testicles.

Results

Laboratory findings were unremarkable except for a slightly elevated luteinizing hormone, which was normal on repeat testing. Because of the picture of unexplained gynecomastia, laboratory findings, and low-volume testis, a diagnosis of KS was considered. Chromosomal analysis revealed a rare 45,X/46,XY/47,XXY/48,XXYY/48,XXXY KS mosaic.

Conclusions

KS phenotypes are largely variable, and their association with PHPT remains to be elucidated.

Endocrine, sexual and reproductive functions in patients with Klinefelter syndrome compared to non-obstructive azoospermic patients

AIMS

We aimed to investigate fertilisation rates, quality of embryo, pregnancy and live birth rates, endocrine, sexual function, psychological status and quality of life of cases diagnosed with Klinefelter syndrome (KS).

METHODS

Clinical findings, hormone values and semen analyses in patients with nonmosaic KS (Group 1, n = 121) and those with non-genetic nonobstructive azoospermia (NOA) (Group 2, n = 178) were retrospectively analysed. Sperm retrieval outcomes with microdissection testicular sperm extraction (micro-TESE), fertilisation rates and embryo quality, pregnancy, abortion and live birth rates were compared. Sexual functions were assessed using IIEF-15, quality of life was evaluated and psychological status was assessed.

RESULTS

There was no difference in terms of age between groups. Sperm retrieval rates was 38% and 55.6% in Groups 1 and 2, respectively (P = .012). Sperm retrieval rates were higher in Group 1 before 31.5 years than in Group 2 (AUC = 0.620 and 0.578). Compared to Group 2, the fertilisation rate was low in Group 1, whereas embryo quality was similar. Live birth rates were 12.5% and 23% in Groups 1 and 2, respectively (P = .392). The education level, libido, erectile functions and general health satisfaction were lower in Group 1 than in Group 2 (P < .005). Depression and anxiety levels were higher in Group 2 than Group 1 (P < .001).

CONCLUSION

Higher sperm retrieval rate has been achieved in Group 1 younger than 31.5 years. Similar embryo quality is provided between groups. Sexual dysfunction and psychiatric problems were higher in Group 1, with lower satisfaction and general health than Group 2. Patients with KS should be monitored not only with their reproductive functions but also with their general health status.

Non-organ-specific autoimmunity in adult 47,XXY Klinefelter patients and higher-grade X-chromosome aneuploidies

Current literature regarding systemic autoimmune diseases in X-chromosome aneuploidies is scarce and limited to case reports. Our aim was to evaluate the frequency of anti-nuclear (ANAs), extractable nuclear (ENA), anti-double-stranded DNA (dsDNAs), anti-smooth muscle (ASMAs) and anti-mitochondrial (AMAs) antibodies in a large cohort of adults with Klinefelter's syndrome (KS, 47,XXY) and rare higher-grade sex chromosome aneuploidies (HGAs) for the first time. Sera from 138 X-chromosome aneuploid patients [124 adult patients with 47,XXY KS and 14 patients with HGA (six children, eight adults)] and 50 age-matched 46,XY controls were recruited from the Sapienza University of Rome (2007-17) and tested for ANAs, ENAs, anti-dsDNAs, ASMAs and AMAs. Non-organ-specific immunoreactivity was found to be significantly higher in patients with 47,XXY KS (14%) than in the controls (2%, p = 0.002). Among all the antibodies investigated, only ANAs were observed significantly more frequently in patients with 47,XXY KS (12.1%) than in the controls (2%, p = 0.004). No anti-dsDNA immunoreactivity was found. Stratifying by testosterone replacement therapy (TRT), non-organ-specific autoantibody frequencies were higher in TRT-naive (p = 0.01) and TRT-treated groups than in controls. No patients with HGA were found positive for the various autoantibodies. Non-organ-specific autoantibodies were significantly present in 47,XXY adult patients. Conversely, HGAs did not appear to be target of non-organ-specific immunoreactivity, suggesting that KS and HGAs should be considered as two distinct conditions. The classification and diagnosis of systemic autoimmune diseases is frequently difficult. To support a correct clinical evaluation of KS disease and to prevent eventual secondary irreversible immune-mediated damages, we highlight the importance of screening for non-organ-specific autoimmunity in Klinefelter's syndrome.

Prenatal Genetic Diagnosis of a Sex Chromosome Aneuploidy: Parent Experiences

Sex chromosome aneuploidies (SCAs) occur in 1 in every 400 births. SCAs are highly variable and have uncertain prognoses, complicating the delivery of prenatal cell-free DNA (cfDNA) results or diagnosis following amniocentesis or chorionic villus sampling. Using a mixed-methods approach, we explored the experiences of parents receiving a prenatal diagnosis of a fetus with SCA. Responses to open-ended questions were qualitatively analyzed. Of the 323 parents who completed the survey, 122 received a prenatal diagnosis and answered at least one open-ended question. Most parents did not recall being informed that cfDNA screening or amniocentesis could reveal the presence of a SCA prior to testing and described feeling unprepared for a positive result. Variation was found between parents who were delivered a diagnosis by a genetic professional versus other clinical specialties. Many parents expressed that the diagnosis was delivered in a way that emphasized the negative attributes of the SCA and that they were provided limited support materials. Parents who received a prenatal diagnosis of a SCA expressed a desire for more supportive delivery of prenatal diagnosis that focuses on parental education and nuanced discussion of potential phenotypes. Genetic counselors should be aware of the range of parental experiences when receiving a SCA diagnosis from non-genetic providers. Prenatal SCA diagnoses are predicted to increase as prenatal cfDNA screening becomes more widely used. Collaborations for greater provider education and comprehensive materials on SCAs are essential to facilitate the delivery of SCA diagnoses and improve parent understanding and support.

Oncologic manifestations of Klinefelter syndrome

Klinefelter syndrome (47,XXY) has a prevalence of approximately 1 in 500 males. It is a condition characterized by an extra X chromosome and is an underdiagnosed clinical entity. Inactivation of genes enables their escape from regulatory mechanisms, which can result in such classic physical manifestations as hypogonadism, gynecomastia, infertility, and various hormonal and physical abnormalities. While the endocrine manifestations of 47,XXY are well-known, the oncologic manifestations have received less attention. An association between cancer and 47,XXY has not as yet been clearly defined, with variability noted in the prevalence of different malignancies in 47,XXY patients. The mechanisms underlying these altered oncologic risks are still under debate. Some of the proposed explanations include hormone imbalance, developmental malfunctions, and failed DNA repair mechanisms. However, the recognition of the oncological associations linked to 47,XXY could be helpful. Screening measures in certain malignancies may enable an earlier diagnosis of 47,XXY and the implementation of more customized care in 47,XXY and the mosaic variants.. The data for this review was compiled from relevant PubMed articles published within the last three decades and organized based on cancer type.

48,XXYY syndrome presenting with long-term infertility and newly observed neck deformities: a case report

Background

Long-term infertility can be attributed to many factors, with the genetic factor being the most overlooked due to its many nonspecific morphological or endocrine signs. We present a rare case of a patient with progressive testicular failure associated with 48,XXYY syndrome.

Case presentation

A 39-year-old Arab man presented to our fertility clinic for fertility treatment. He was diagnosed with primary infertility, which had been present for 20 years at the time of presentation. Our patient had nonspecific morphological features of an abnormally wide neck with front slouching neck posture, clinodactyly of the third finger, and had moderate hypoandrogenemic features. A semen analysis revealed azoospermia. Genetic tests for azoospermia, including sex-determining region Y (SRY) detection and chromosome Y microdeletion, revealed no deletion present on the Y chromosome. Karyotyping was used and our patient was diagnosed with 48,XXYY syndrome.

Conclusion

Genetic testing (karyotyping and so on) played a key role in the diagnosis of our patient with long-term primary infertility secondary to 48,XXYY syndrome, and should play a vital role in all cases of long-term infertility, especially when presentation is accompanied by endocrine, skeletal, or morphological symptoms, signifying an underlying genetic factor.

Generation of two iPSC lines (KAUSTi001-A, KAUSTi002-A) from a rare high-grade Klinefelter Syndrome patient (49-XXXXY) carrying a balanced translocation t(4,11) (q35,q23)

Klinefelter Syndrome (KS) is the most common aneuploidy in humans (prevalence: 85-250 per 100,000 born males) and is characterized by one or more supernumerary X-chromosomes (47-XXY, 48-XXXY and 49-XXXXY karyotypes). KS is a multisystemic disorder associated to multiple phenotypic features including cardiac abnormalities, infertility, mental retardation, diabetes and increased cancer risk. Using a non-integrative mRNAs reprogramming approach, we generated two iPSC lines 48-XXXY and 49-XXXXY from a non-mosaic 49-XXXXY KS patient carrying a balanced translocation t(4,11) (q35,q23). These iPSC lines provide a unique cellular platform to study the molecular mechanisms underlying KS pathophysiology.

European academy of andrology guidelines on Klinefelter Syndrome Endorsing Organization: European Society of Endocrinology

BACKGROUND

Knowledge about Klinefelter syndrome (KS) has increased substantially since its first description almost 80 years ago. A variety of treatment options concerning the spectrum of symptoms associated with KS exists, also regarding aspects beyond testicular dysfunction. Nevertheless, the diagnostic rate is still low in relation to prevalence and no international guidelines are available for KS.

OBJECTIVE

To create the first European Academy of Andrology (EAA) guidelines on KS.

METHODS

An expert group of academicians appointed by the EAA generated a consensus guideline according to the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) system.

RESULTS

Clinical features are highly variable among patients with KS, although common characteristics are severely attenuated spermatogenesis and Leydig cell impairment, resulting in azoospermia and hypergonadotropic hypogonadism. In addition, various manifestations of neurocognitive and psychosocial phenotypes have been described as well as an increased prevalence of adverse cardiovascular, metabolic and bone-related conditions which might explain the increased morbidity/mortality in KS. Moreover, compared to the general male population, a higher prevalence of dental, coagulation and autoimmune disorders is likely to exist in patients with KS. Both genetic and epigenetic effects due to the supernumerary X chromosome as well as testosterone deficiency contribute to this pathological pattern. The majority of patients with KS is diagnosed during adulthood, but symptoms can already become obvious during infancy, childhood or adolescence. The paediatric and juvenile patients with KS require specific attention regarding their development and fertility.

CONCLUSION

These guidelines provide recommendations and suggestions to care for patients with KS in various developmental stages ranging from childhood and adolescence to adulthood. This advice is based on recent research data and respective evaluations as well as validations performed by a group of experts.

Isolated and combined genetic tremor syndromes: a critical appraisal based on the 2018 MDS criteria

The 2018 consensus statement on the classification of tremors proposes a two-axis categorization scheme based on clinical features and etiology. It also defines "isolated" and "combined" tremor syndromes depending on whether tremor is the sole clinical manifestation or is associated with other neurological or systemic signs. This syndromic approach provides a guide to investigate the underlying etiology of tremors, either genetic or acquired. Several genetic defects have been proven to cause tremor disorders, including autosomal dominant and recessive, X-linked, and mitochondrial diseases, as well as chromosomal abnormalities. Furthermore, some tremor syndromes are recognized in individuals with a positive family history, but their genetic confirmation is pending. Although most genetic tremor disorders show a combined clinical picture, there are some distinctive conditions in which tremor may precede the appearance of other neurological signs by years or remain the prominent manifestation throughout the disease course, previously leading to misdiagnosis as essential tremor (ET). Advances in the knowledge of genetically determined tremors may have been hampered by the inclusion of heterogeneous entities in previous studies on ET. The recent classification of tremors therefore aims to provide more consistent clinical data for deconstructing the genetic basis of tremor syndromes in the next-generation and long-read sequencing era. This review outlines the wide spectrum of tremor disorders with defined or presumed genetic etiology, both isolated and combined, unraveling diagnostic clues of these conditions and focusing mainly on ET-like phenotypes. Furthermore, we suggest a phenotype-to-genotype algorithm to support clinicians in identifying tremor syndromes and guiding genetic investigations.

Sexual and developmental aspects of 49, XXXXY Syndrome: A case report

49, XXXXY syndrome is one of the rarest sexual chromosome disorders, with an incidence of 1:85000-100000 males. It is caused by nondisjunction of the X chromosomes in both meiosis I and II. Early intervention is vital to improve behavioural, neural and sexual well-being. Information about sexual and developmental aspects is extremely limited in previous literature. We present a case of a 26-month-old male child presenting with hypotonia, micropenis and bilateral cryptorchidism. Karyotype study was done in Jordan at the age of 16 months and revealed 49, XXXXY syndrome. Global developmental delay, hypotonia and weak truncal muscles were noted on examination. Growth parameters were within normal limits. Kidney ultrasound revealed findings suggestive of Vesicoureteral reflux. Laboratory investigations revealed hypoandrogenism with normal 17-OHP levels. This study reviews current knowledge about sexual and developmental characteristics of 49, XXXXY syndrome.

Early neurodevelopmental and medical profile in children with sex chromosome trisomies: Background for the prospective eXtraordinarY babies study to identify early risk factors and targets for intervention

Sex chromosome trisomies (SCT), including Klinefelter syndrome/XXY, Trisomy X, and XYY syndrome, occur in 1 of every 500 births. The past decades of research have resulted in a broadening of known associated medical comorbidities as well as advances in psychological research. This review summarizes what is known about early neurodevelopmental, behavioral, and medical manifestations in young children with SCT. We focus on recent research and unanswered questions related to the risk for neurodevelopmental disorders that commonly present in the first years of life and discuss the medical and endocrine manifestations of SCT at this young age. The increasing rate of prenatal SCT diagnoses provides the opportunity to address gaps in the existing literature in a new birth cohort, leading to development of the eXtraordinarY Babies Study. This study aims to better describe and compare the natural history of SCT conditions, identify predictors of positive and negative outcomes in SCT, evaluate developmental and autism screening measures commonly used in primary care practices for the SCT population, and build a rich data set linked to a bank of biological samples for future study. Results from this study and ongoing international research efforts will inform evidence-based care and improve health and neurodevelopmental outcomes.

Rare sex chromosome variation 48,XXYY: An integrative review

While the most common Sex Chromosome Aneuploidy (SCA) is 47,XXY, other variations, such as 48,XXYY, are less studied, perhaps due to its rarity. 48,XXYY occurs with an estimated prevalence of 1:18,000-40,000 male births. This SCA is associated with a variety of complex physical, psychological, and neuroanatomical findings. The purpose of this integrative review is to summarize the available evidence related to 48,XXYY and identify gaps in the literature. This study utilized integrative review and PRISMA-guided methodology to search six databases for information pertaining to 48,XXYY. There were no exclusion criteria related to design methodology, given the paucity of available research. Among 397 articles reviewed for potential inclusion, 30 articles remained after inclusion and exclusion criteria were applied. Seven of these articles concentrated solely on participants with 48,XXYY. Literature was summarized into categories of physical phenotype, psychosocial, behavioral, neurocognitive, and brain function. Clinical description of 48,XXYY has evolved over time to develop a deeper understanding of this complex disorder. Large gaps remain, especially a lack of experimental studies, clinical guidelines, and treatments. Additionally, few studies explore methodologies such as interviews or self-report surveys in this population. 48,XXYY presents with a wide spectrum of physical, psychological, and neurocognitive symptoms, and frequently requires complex interdisciplinary care. In order to better understand this disorder and to appropriately treat the individuals affected by it, future research should focus on experimental studies and research that utilizes a variety of methods, including participant interviews and patient-report surveys.

Obesity with High Body Mass Index Does Not Influence Sperm Retrieval in Males with Azoospermia

BACKGROUND The aim of this study was to evaluate the influence of male body mass index (BMI) on the retrieval of sperm from azoospermic patients who were undergoing testicular sperm extraction (TESE). MATERIAL AND METHODS The study included retrospective data of male patients suffering from non-obstructive azoospermia (NOA). Age, BMI, testicular volumes, the serum concentration of the follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and prolactin were investigated and collected. RESULTS A total of 75 azoospermic males were evaluated between 2014 and 2019, including 35 patients (46.7%) with positive sperm retrieval. The majority of patients (57.3%) had normal BMI (between 20 kg/m² and 25 kg/m²) or first degree obesity (from 25 kg/m² to 30 kg/m²). No statistically significant correlation between BMI and positive sperm retrieval or hormone levels (LH, FSH, SHBG, prolactin) were found. However, lower serum testosterone levels were observed in patients with higher BMI (P=0.035). Receiver operating characteristic curve analysis showed that none of the hormones could potentially predict the positive outcome of TESE. CONCLUSIONS The hormonal levels or patient's BMI could not predict positive sperm retrieval outcome, however a negative correlation between serum testosterone and BMI levels was calculated implicating influence on fertility.

Integration and reanalysis of transcriptomics and methylomics data derived from blood and testis tissue of men with 47,XXY Klinefelter syndrome indicates the primary involvement of Sertoli cells in the testicular pathogenesis

Klinefelter syndrome (KS; 47,XXY) is the most common sex chromosomal anomaly and causes a multitude of symptoms. Often the most noticeable symptom is infertility caused by azoospermia with testicular histology showing hyalinization of tubules, germ cells loss, and Leydig cell hyperplasia. The germ cell loss begins early in life leading to partial hyalinization of the testis at puberty, but the mechanistic drivers behind this remain poorly understood. In this systematic review, we summarize the current knowledge on developmental changes in the cellularity of KS gonads supplemented by a comparative analysis of the fetal and adult gonadal transcriptome, and blood transcriptome and methylome of men with KS. We identified a high fraction of upregulated genes that escape X-chromosome inactivation, thus supporting previous hypotheses that these are the main drivers of the testicular phenotype in KS. Enrichment analysis showed overrepresentation of genes from the X- and Y-chromosome and testicular transcription factors. Furthermore, by re-evaluation of recent single cell RNA-sequencing data originating from adult KS testis, we found novel evidence that the Sertoli cell is the most affected cell type. Our results are consistent with disturbed cross-talk between somatic and germ cells in the KS testis, and with X-escapee genes acting as mediators.

Current survey of early childhood intervention services in infants and young children with sex chromosome aneuploidies

Sex chromosome aneuploidies (SCAs) are the most commonly occurring aneuploidies in children with a collective prevalence rate of 1 in 500 live births. Prior research has documented SCAs are associated with an increased risk for early expressive language and gross motor delays, learning disorders, ADHD, autism spectrum disorder, anxiety, and executive function problems. Although SCAs have been historically underdiagnosed in young children, recent advances in noninvasive prenatal testing have resulted in an increasing nationwide cohort of infants with confirmed diagnoses. Consequently, early childhood support systems must prepare for an influx of children with known risks for associated developmental delays and potential school problems. This national survey aimed to update our understanding of current early childhood intervention services for young children with SCA in the United States and to describe parent perspectives and priorities. Descriptive statistics, chi-square tests, and logistic regression models controlling for parent education revealed a majority of respondents reported receiving public early childhood intervention services with speech therapy as the most common service. There were significant differences in early childhood intervention services by timing of diagnosis (prenatal vs. postnatal), number of sex chromosomes (trisomy vs. tetra/pentasomy), and geographic location. Parents described interventions as desirable and effective yet also difficult to obtain due to issues with the SCA phenotype, lack of provider knowledge, and challenges navigating the intervention systems. Results support the need for enhanced provider training in SCAs, policy change for early childhood intervention qualification criteria for SCA conditions, and collaboration between medical and early childhood settings.

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.