Speech and language development in children with 49,XXXXY syndrome

49,XXXXY is the rarest X and Y chromosomal variation and is frequently characterized by expressive and receptive language dysfunction, low muscle tonus, and intellectual deficits. Due to the low incidence of this disorder, comprehensive studies analyzing the specific aspects of the speech and language phenotype in these boys have been uncommon. This is the first in-depth investigation of the speech and language profiles in a large cohort of boys with 49,XXXXY. Based on the clinical judgment of speech and language pathologists, there was an increased incidence (91.8%) of Childhood Apraxia of Speech (CAS), which has not been previously described in this disorder. In preschool boys, some significant differences were demonstrated between boys who received early hormonal treatment (n = 16) and untreated boys (n = 4) on the language scales (p = .047) on the Bayley Scales of Infants and Toddlers, as well as significant differences between treated (n = 13) and untreated boys (n = 8) on the Expressive One Word Picture Vocabulary Test (p = .008). No significant differences between treatment groups were found in school age children, however, treated groups demonstrated less discrepancies between expressive and receptive language. More research and larger samples are needed to determine the extent of the impact of testosterone treatment on boys with 49,XXXXY. This study identifies CAS as a potential explanation for the significant expressive language dysfunction and subsequent behavioral dysfunction. These findings may assist in facilitating more targeted treatment and improved outcomes for boys with 49,XXXXY.

Evidence of intrauterine growth restriction and growth hormone deficiency in 49,XXXXY syndrome

49,XXXXY is an X and Y chromosome variation that occurs in 1:85,000 to 1:100,000 live male births. Previous case studies have described boys with this disorder to be shorter than average when compared with boys with only one extra chromosome and with the mean stature in a small cohort reported to range from the seventh to 33rd percentile. The origin behind the possible differences in height between boys with 47,XXY and 49,XXXXY is currently unknown, however one study hypothesized that it was due to a difference in the expression of the SHOX gene. This study reports on the anthropometric measurements of 84 boys with 49,XXXXY. Forty-five percent of children with 49,XXXXY were found to be below the third percentile in height at the time of evaluation. In addition, 7.14% of the cohort were diagnosed and given treatment for growth hormone deficiency (GHD). The analysis of this cohort demonstrates that the below average heights seen throughout childhood in this population potentially begins prenatally and suggests that boys with 49,XXXXY may be at a higher risk for intrauterine growth restriction (IUGR) and GHD. Future research is needed to investigate the etiology of the poor growth in boys with 49,XXXXY and evaluate the incidence of GHD and IUGR in this population.

Musculoskeletal abnormalities in a large international cohort of boys with 49,XXXXY

49,XXXXY is the rarest X and Y chromosomal variation, with an incidence of 1 in 80,000-100,000 live male births and has been associated with numerous musculoskeletal abnormalities. Data was collected from an international cohort of boys with 49,XXXXY over 10 years. Children were evaluated by a multidisciplinary team consisting of a pediatric orthopedist, a neurogeneticist, a neurodevelopmentalist, and two physical therapists. Increased rates of torticollis (32.4%), hamstring tightness (42%), radioulnar synostosis (67.6%), pes planus (65.2%), and other foot abnormalities (86.9%) were observed. Several anomalies increased with age, specifically hamstring tightness, kyphosis, and scoliosis. The elucidation of the orthopedic profile of this population is necessary in order to provide healthcare providers with current medical information. This research further supports the necessity for the comprehensive multidisciplinary treatment of boys with 49,XXXXY.

Behavioral phenotype of 49,XXXXY syndrome: Presence of anxiety-related symptoms and intact social awareness

49,XXXXY is a rare X and Y chromosome variation that occurs in 1:85,000 to 1:100,000 live male births and is notable for variable motor, speech, and behavioral deficits. Case studies have described boys with this disorder as shy, impulsive, and aggressive with low frustration tolerances; however, previous studies have been limited due to cohort size. This study reports on the largest cohort of boys with 49,XXXXY to date with an emphasis on the prevalence of anxiety-related symptoms and sociability from preschool to adolescence. The Child Behavior Checklist, Behavior Rating Inventory of Executive Function, 2nd edition, and Social Responsiveness Scale, 2nd edition were completed by parents on a cohort of 69. The cohort demonstrated deficits in social cognition and communication beginning in preschool, however, presented with consistent social awareness and motivation for social activities not previously appreciated in this disorder. In addition, signs of anxiety presented during preschool years and increased in severity with age, particularly in internalizing problems. Boys with 49,XXXXY presented with wide behavioral variability across all ages and domains. Further research into the potential influences of culture, birth order, biological treatment, and frequency of services is needed to better define the behavioral phenotype of children with this disorder.

The incidence of anxiety symptoms in boys with 47,XXY (Klinefelter syndrome) and the possible impact of timing of diagnosis and hormonal replacement therapy

47,XXY (Klinefelter syndrome) is the most common X and Y chromosomal variation (1:660 males). The incidence of anxiety disorders and the impact of hormonal replacement therapy (HRT) is not well understood. Child Behavior Checklist and Screen for Childhood Anxiety Related Emotional Disorders were completed by parents of 80 boys with 47,XXY. Forty received HRT prior to 10 years of age while 40 did not. HRT (22.5%) received early hormonal treatment prior to 18 months. About 32.5% received hormone booster treatment between 5 and 10 years. The remaining 42.5% received both. There were fewer reported social (p = .015), thought (p = .012), and affective problems (p = .048) in treated boys when compared to untreated. Boys with both treatments demonstrated fewer symptoms on anxious/depressed scale (p = .001) compared to those with early treatment only. Within the treated group, prenatally diagnosed showed fewer indications of anxiety problems (p = .02) than their postnatal counterparts. This comparative, cross-sectional study expands previous findings on the possible positive effect of HRT in boys with 47,XXY. Anxiety disorders appear to be a penetrant aspect of the 47,XXY phenotype. Further investigation is warranted to explore the relationship between biological treatment and individual responses to HRT to develop more personalized and precise medicine.