Klinefelter syndrome: an unusual diagnosis in pediatric patients.
OBJECTIVE
To identify clinical and laboratory data which differentiate Klinefelter syndrome (KS) patients according to age group.


METHODS
The study included all cases of hypogonadism, gynecomastia and/or infertility whose karyotype was performed at a university hospital from January 1989 to December 2011, in a total of 105 subjects. The following data were retrospectively analyzed: age at first visit, ratio of arm span to height, pubic hair, gynecomastia, testicular volume, luteinizing hormone (LH), follicle stimulating hormone (FSH), total testosterone (T), and spermiogram.


RESULTS
During the study period, 33 patients were diagnosed with Klinefelter syndrome (KS+) and 72 were not (KS-). Out of all KS cases, only seven (21.2%) were diagnosed before 20 years old and two (6.1%) before 10 years old. Age at first consultation (in years) was similar in both groups (KS+ = 31.3±12.9 and KS- = 27.6±12.1), as were ratio of arm span to height and frequency of gynecomastia. However, in KS+ patients, pubic hair was less developed, testicular volume was smaller and testosterone levels were lower, while LH and FSH levels and frequency of azoospermia were higher.


CONCLUSIONS
Klinefelter syndrome is both an under and late diagnosed condition. The most important data for diagnosis are testicular volume, hormone levels and presence of azoospermia in spermiogram, especially in puberty and adult life.
Departamento de Pediatria, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil.
Bruna J
BJ
Tincani
Bruno R
BR
Mascagni
Roberto D P
RD
Pinto
Guilherme
G
Guaragna-Filho
Carla C T S
CC
Castro
Letícia E
LE
Sewaybricker
Nilma L
NL
Viguetti-Campos
Antonia P
AP
Marques-de-Faria
Andréa T
AT
Maciel-Guerra
Gil
G
Guerra-Júnior
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D053713:Azoospermia / Q000175:diagnosis; D016009:Chi-Square Distribution; D002648:Child; D057210:Delayed Diagnosis; D006177:Gynecomastia / Q000175:diagnosis; D006801:Humans; D007621:Karyotyping; D007713:Klinefelter Syndrome / Q000175:diagnosis* / Q000235:genetics; D008297:Male; D008875:Middle Aged; D011628:Puberty, Delayed; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D055815:Young Adult