Clinical Presentation of Klinefelter's Syndrome: Differences According to Age

Abstract

The aim of the study was to establish the characteristics of presentation of 94 patients with Kinelfelter's syndrome (KS) referred to the endocrinologist at different ages. The diagnosis of KS was more frequent in the age group between 11 and 20 years (46.8%). Most of the patients (83.7%) showed the classic 47,XXY karyotype and 7.1% showed a 47,XXY/46,XY mosaicism. Half of the patients younger than 18 years presented mild neurodevelopmental disorders. The most frequent clinical findings were cryptorchidism in prepubertal patients, and small testes, cryptorchidism, and gynecomastia in pubertal patients. FSH, LH, AMH, and inhibin B levels were normal in prepubertal patients and became abnormal from midpuberty. Most adults were referred for small testes, infertility, and gynecomastia; 43.6% had sexual dysfunction. Testosterone levels were low in 45%. Mean stature was above the 50th percentile, and 62.5% had BMI ≥25.0 kg/m2. In conclusion, the diagnosis of Klinefelter syndrome seems to be made earlier nowadays probably because pediatricians are more aware that boys and adolescents with neuro-developmental disorders and cryptorchidism are at increased risk. The increasing use of prenatal diagnosis has also decreased the mean age at diagnosis and allowed to get insight into the evolution of previously undiagnosed cases, which probably represent the mildest forms. In adults average height and weight are slightly higher than those in the normal population. Bone mineral density is mildly affected, more at the spine than at the femoral neck level, in less than half of cases.

Klinefelter syndrome: an unusual diagnosis in pediatric patients

“…O HC-UNICAMP atende a população de uma região com mais de 5 milhões de habitantes, e para esse volume de atendimento deveríamos ter registrado muito mais que 33 diagnósticos de SK em 23 anos (cerca de três casos diagnosticados a cada 2 anos), indicando que ou os pacientes procuram pouco o serviço médico, ou os médicos pensam pouco nesse diagnóstico. Apesar de aparentemente pequena, a casuística do presente estudo é parecida com a maioria dos estudos recentes 1,3,8,14 , onde a maior foi de 98 casos 10 Todos os indivíduos avaliados abaixo dos 10 anos de idade foram encaminhados por deficiência intelectual e/ou atraso do desenvolvimento neuromotor. Déficits cognitivos específicos na linguagem e na função executiva são parte do fenótipo da SK 15 .…”

“…Os achados clínicos principais, presentes em quase todos os indivíduos com SK, são os testículos pequenos, a azoospermia e o aumento das gonadotrofinas, em especial do follicle stimulating hormone (FSH); porém, outros achados, como ginecomastia, atraso puberal, pilificação pubiana e corporal diminuídas, micropênis, alta estatura, aumento da envergadura em relação à estatura, distúrbios de aprendizado, doenças psiquiátricas, doença venosa periférica, obesidade abdominal, síndrome metabólica, maior risco de doenças autoimunes e câncer, podem ser observados com diferentes frequências de acordo com a população avaliada, a faixa etária incluída e o cariótipo encontrado 1,[3][4][5][6][7][8][9][10] .…”

Pre-pubertal diagnosis of Klinefelter syndrome due to peno-scrotal malformations; Case report and review of literature

“…This was slightly lower than 55.5% to 69% range in the Klinefelter syndrome cases diagnosed before puberty and without penoscrotal malformations. 4,9 The genital malformations in Klinefelter syndrome may be related its high heritability and to the maternal administration of estrogen or anti-androgen. 10 However, in our reported cases, maternal and family history was negative.…”

“…2,3 Klinefelter presentation in childhood, due to genital malformations, is rare. 4 We present a case diagnosed during investigations for penoscrotal transposition and hypospadias and provide a review of similar cases in the literature.…”

Asociación de craneofaringioma y síndrome de Klinefelter en la transición puberal: un desafío diagnóstico

“…En efecto, el hipopituitarismo secundario al tratamiento del craneofaringioma i m p i d i ó o b s e r v a r u n a e l e v a c i ó n d e l a s gonadotropinas, habitual a partir del estadio G III de desarrollo puberal, momento definido como pubertad media. [4][5][6][7][8][9][10][11][12][13][14][15] Este caso clínico nos ilustra la importancia del seguimiento multidisciplinario, pediátrico y en el periodo de transición a adulto, y permite así un diagnóstico y manejo apropiados de hipogonadismo en estos pacientes. n…”