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

Research Priorities of Individuals and Families With Sex Chromosome Aneuploidies

Sex chromosome aneuploidies (SCAs) are chromosomal variations that result from an atypical number of X and/or Y chromosomes. Combined, SCAs affect ~1/400 live births, including individuals with Klinefelter syndrome (47, XXY), Turner syndrome (45, X and variants), Double Y syndrome (47, XYY), Trisomy X (47, XXX), and rarer tetrasomies and pentasomies. Individuals with SCAs experience a wide variety of physical health, mental health, and healthcare experiences that differ from the standard population. To understand the priorities of the SCA community we surveyed participants in two large SCA registries, the Inspiring New Science in Guiding Healthcare in Turner Syndrome (INSIGHTS) Registry and the Generating Advancements in Longitudinal Analysis in X and Y Variations (GALAXY) Registry. 303/629 (48.1% response rate) individuals from 13 sites across the United States responded to the survey, including 251 caregivers and 52 self-advocates, with a range of ages from 3 weeks to 73 years old, and representation from all SCA groups (Turner syndrome, XXX, XXY, XYY, XXYY, and combined rare tetrasomies and pentasomies). Results demonstrate the priorities for physical health and emotional/behavioral health identified by the SCA community, as well as preferred types of research. All SCA subtypes indicated intervention studies as the top priority, emphasizing the need for researchers to focus on clinical treatments in response to priorities of the SCA community.

Klinefelter Syndrome: A Review

BACKGROUND

Klinefelter syndrome (KS) is an uncommonly recognised condition typified by gynaecomastia, small testes and aspermatogenesis. It is caused by a supernumerary X chromosome, resulting in a 47 XXY karyotype. Since its first description, the phenotype of KS has evolved and there is a much greater appreciation of the subtle features of the condition.

METHOD

In this review, we explore the phenotype of the KS with particular consideration to patients with pre-natal and early infancy diagnosis, given that this is becoming increasingly common. The current understanding of the genetic mechanisms of KS, caused by supernumerary X chromosome are explored and the genotype-phenotype correlation are discussed.

RESULTS

The implications of the condition both in childhood and later development are explored in detail, with particular focus on social and educational implications. Potential treatments, with emphasis on preservation of fertility are discussed. We highlight the optimal therapeutic conditions in which fertility preservation is most likely to be achieved, compared to those which can be more challenging. Finally, we discuss the other health challenges which can be associated with KS. These include poor bone health, diabetes, cardiovascular complications, and malignancy. The challenges in managing these co-morbid conditions and most up-to-date management recommendations are also explored.

Uniparental maternal tetrasomy X co-occurrence with paternal nondisjunction: investigation of the origin of 48,XXXX

Tetrasomy X or 48,XXXX is a rare sex chromosome aneuploidy. The parental origin of tetrasomy X in a female patient with developmental delay was analyzed; all four X chromosomes were derived from the mother, and there were no paternally derived sex chromosomes. This finding indicates a rare incidental co-occurrence of maternal and paternal nondisjunction or polysomy rescue. The mechanism of 48,XXYY, which is related to developmental delay in males, was analyzed for comparison.

Research Priorities of Individuals and Families with Sex Chromosome Aneuploidies

Sex chromosome aneuploidies (SCAs) are chromosomal variations that result from an atypical number of X and/or Y chromosomes. Combined, SCAs affect ~1/400 live births, including individuals with Klinefelter syndrome (47,XXY), Turner syndrome (45,X and variants), Double Y syndrome (47,XYY), Trisomy X (47,XXX), and rarer tetrasomies and pentasomies. Individuals with SCAs experience a wide variety of physical health, mental health, and healthcare experiences that differ from the standard population. To understand the priorities of the SCA community we surveyed participants in two large SCA registries, the Inspiring New Science in Guiding Healthcare in Turner Syndrome (INSIGHTS) Registry and the Generating Advancements in Longitudinal Analysis in X and Y Variations (GALAXY) Registry. 303/629 (48.1% response rate) individuals from 13 sites across the United States responded to the survey, including 251 caregivers and 52 self-advocates, with a range of ages from 3 weeks to 73 years old and represented SCAs including Turner syndrome, XXX, XXY, XYY, XXYY, and combined rare tetrasomies and pentasomies. Results demonstrate the priorities for physical health and emotional/behavioral health identified by the SCA community, as well as preferred types of research. All SCA subtypes indicated intervention studies as the top priority, emphasizing the need for researchers to focus on clinical treatments in response to priorities of the SCA community.

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.

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.

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.

The timely diagnosis of 49, XXXXY with the combined detection of MLPA, karyotype, and QF-PCR in a newborn with multiple congenital malformations: a case report

BACKGROUND

49, XXXXY is a rare sex chromosomal aneuploidy syndrome. The patients usually are diagnosed several months or years after birth. Herein a neonate with respiratory distress and multiple malformations was diagnosed with 49, XXXXY syndrome by an economical method of multiplex ligation-dependent probe amplification (MLPA) followed karyotype analysis.

CASE DESCRIPTION

An infant was born via spontaneous vaginal delivery at 41⁺³ weeks' gestation and hospitalized due to neonatal asphyxia. He was the first child to a 24-year-old gravida1, para1 (G1P1) mother. The newborn was characterized low birth weight (2.4 Kg, below the 3^rd percentile), and an Apgar score of 6 at 1 minute, 8 at 5 minutes, and 9 at 10 minutes. The physical examinations of the patient revealed ocular hypertelorism, epicanthal folds, low nasal bridge, high-arched palate, cleft palate, micrognathia, low-set ears, microcephaly, hypotonia, and micropenis. Echocardiography revealed atrial septal defects (ASD). The brainstem auditory evoked potential (BAEP) reflected auditory function impairment. Genetic testing methods, including MLPA, karyotyping, and quantitative fluorescent polymerase chain reaction (QF-PCR), were performed for definitive diagnosis, which confirmed 49, XXXXY syndrome.

CONCLUSIONS

The presentation of the 49, XXXXY newborn was atypical, they may only include low birth weight, multiple malformations and a characteristic facial appearance which were consistent with the characteristics of autosomal and sex chromosome aneuploidies. At this time, the economical and rapid method of MLPA to screen the number of chromosome, and then choose the appropriate means to make the final diagnosis and improve the quality of life of patients with timely therapy.

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.