Neonatal 48,XXYY syndrome can present with both ambiguous genitalia and Tetralogy of Fallot, a striking and previously unreported association. This case broadens the phenotypic spectrum and underscores the importance of integrating genetic and cardiac evaluation in all neonates with disorders of sex development.

48,XXYY syndrome is a rare sex chromosome aneuploidy (SCA) condition affecting 1 in 18,000-40,000 male births. Clinical features include tall stature, hypergonadotropic hypogonadism (testosterone deficiency), infertility, developmental delays, learning disabilities, and intellectual impairment. Co-occurring behavior and mental health challenges are common in this population, with high rates of attention-deficit hyperactivity disorder (ADHD), anxiety, depression, sleep disorders, irritability, and aggressive behaviors. We evaluated psychotropic medication use by parent report and retrospective chart review. Treatment success was defined as a positive response per parent report, positive clinician rating, or a treatment duration of at least 6 months. Nearly three-quarters of participants (71/101) with a median age of 15.9 (range 4.5-38 years) had received psychotropic medications. The most common medication classes used were stimulant ADHD medications (78.9% of those with medication use), with a median age of first use of 9 years ([IQR] 7, 11 years), followed by anti-anxiety/antidepressant medications (60.6%), with a median age of first use of 10 years ([IQR] 8, 14 years). Treatment success rates ranged from 43.9% to 84.2% for individual medication trials. Subsequent trials of medications within the same class improved success rates per person in all medication classes except for sleep and mood stabilizer medications. Treatment failure due to side effects was greatest among neuroleptics/atypical antipsychotics, whereas treatment failure due to inefficacy was greatest among anti-anxiety/antidepressants and mood stabilizers. The findings of this study suggest that psychotropic medications targeting behavior and mental health are common and overall helpful for individuals with 48,XXYY.

Among sex chromosome aneuploidies, 48, XXYY syndrome is a rare variant. This condition is marked by the existence of an additional X and Y chromosome in males, leading to a diverse range of physical, neurocognitive, behavioral, and psychological manifestations. Typical characteristics include a tall stature and infertility. Other phenotypes include congenital heart defects, skeletal anomalies, tremors, obesity, as well as the potential for type 2 diabetes and/or peripheral vascular disease. A 6-year-old boy, who had been experiencing progressive vision deterioration in both eyes for the past two years, presented with a history of poor vision, delayed motor skills. The patient was diagnosed with micropenis in the pediatric outpatient clinic. Sparse hair, an unusually tall stature and craniofacial dysmorphology characterized by ocular hypertelorism, depressed nasal bridge, and epicanthic folds were observed. Comprehensive ophthalmic examination revealed high myopia and grade 3 macular hypoplasia. Diagnostic investigations including karyotype analysis and whole-exome sequencing identified an anomalous male karyotype comprising two X and two Y chromosomes, confirming a diagnosis of 48, XXYY syndrome. This study underscores the rare association of high myopia and grade 3 macular dysplasia with 48, XXYY syndrome. To our knowledge, this case marks the first recorded instance of macular dysplasia in a patient with 48, XXYY syndrome. This novel finding enhances our understanding of this syndrome's phenotypic variability.

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. 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. 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.

Nonsyndromic hearing loss (NSHL) is the most frequent type of hereditary hearing impairment. Here, we explored the underlying genetic cause of NSHL in a three-generation family using whole-exome sequencing. The proband had concomitant NSHL and rare 48,XXYY Klinefelter syndrome. Genomic DNA was extracted from the peripheral blood of the proband and their family members. Sanger sequencing and pedigree verification were performed on the pathogenic variants filtered by whole-exome sequencing. The function of the variants was analyzed using bioinformatics software. The proband was digenic heterozygous for p.V37I in the GJB2 gene and p.L347I in the MYO7A gene. The proband's mother had normal hearing and did not have any variant. The proband's father and uncle both had NSHL and were compound for the GJB2 p.V37I and MYO7A p.L347I variants, thus indicating a possible GJB2/MYO7A digenic inheritance of NSHL. 48,XXYY Klinefelter syndrome was discovered in the proband after the karyotype analysis, while his parents both had normal karyotypes. Our findings reported a putative GJB2/MYO7A digenic inheritance form of hearing loss, expanding the genotype and phenotype spectrum of NSHL. In addition, this is the first report of concomitant NSHL and 48,XXYY syndrome.