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.

中文翻译：

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49,XXXXY 综合征宫内生长受限和生长激素缺乏的证据

49,XXXXY 是一​​种 X 和 Y 染色体变异，发生在 1:85,000 到 1:100,000 的活男性出生中。以前的案例研究描述了患有这种疾病的男孩与只有一条额外染色体的男孩相比比平均身材矮，并且据报道，在一个小队列中，平均身高在第 7 到第 33 个百分位之间。目前尚不清楚 47,XXY 和 49,XXXXY 男孩之间可能存在身高差异的原因，但一项研究假设这是由于 SHOX 基因的表达差异所致。本研究报告了 84 名 49,XXXXY 男孩的人体测量数据。在评估时，发现 45% 的 49,XXXXY 的儿童身高低于第三个百分位。此外，7。14% 的队列被诊断出并接受了生长激素缺乏症 (GHD) 的治疗。对该队列的分析表明，该人群在整个童年时期看到的低于平均身高的身高可能在产前就开始了，这表明 49,XXXXY 的男孩可能面临更高的宫内生长受限 (IUGR) 和 GHD 风险。未来的研究需要调查 49,XXXXY 男孩生长不良的病因，并评估该人群中 GHD 和 IUGR 的发生率。