[The differential diagnosis of constitutional delay of puberty and hypogonadotropic hypogonadism in boys].

BACKGROUND: The problem of differential diagnosis of constitutional delay of puberty/CDP and hypogonadotropic hypogonadism/HH in boys is discussed, as boys have similar genetic mechanisms and appearance. AIMS: to determine accuracy of the criteria for the differential diagnosis of CDP and HH. MATERIALS: The study included 56 boys 14.4±0.7 years old with delayed puberty (G1P1-3/testicular volume <3 сm3). We excluded patients with hypergonadotropic hypogonadism, treated with sex steroids or gonadotropins for 12 months, with endocrine/somatic diseases affecting puberty. At the first visit, we evaluated anthropometric data, bone age, testicular volume, hormones and the results of the gonadotropin-releasing hormone test (GnRH) agonist test and the human chorionic gonadotropin test (hCG) test. The HH was defined by a testicular volume <3 сm3 after 2 years follow-up. The patients were divided into two groups: the first group with CDP and testicles ≥3 cm3 (n=50) and the second group with HH and testicles <3 cm3 (n=6). RESULTS: At the first visit in boys with CDP corrected target height was less (Me SDS –1.8 vs –0,4, р=0.02), bone age was less (Ме SDS –2.5 vs –0.2 р=0.03), testicular volume was more (Ме 1.9 vs 0.5, p=0.0003), hormones were significantly higher, such as LH (Ме 1.1 vs 0.1 mIU/ml, p=0.0002), FSH (Ме 1.9 vs 0.2 IU/l, p=0.00007), inhibin B (Ме 142.3 vs 31.3 pg/ml, p=0.00009), max LH (Ме 18.9 vs 0.6 mIU/ml, p=0.00007), max LH/FSH (Ме 2.3 vs 0.4, p=0.0002) on the GnRH agonist test and Δ testosterone (Ме 14.4 vs 1.1 nmol/l, p=0.0001) on the hCG test than in boys with HH. The LH ≥0.3 mIU/ml had 86% sensitivity, 100% specificity; max LH/FSH ≥1 – 92% sensitivity, 100% specificity; Δ testosterone ≥2.7 nmol/l on the hCG test – 98% sensitivity, 100% specificity for differential diagnosis of CDP and HH in boys. However, max LH ≥3.5 mIU/ml on the GnRH agonist test, FSH ≥0.5 IU/l, inhibin B ≥58 pg/ml had 100% sensitivity and specificity for diagnosis of CDP. CONCLUSIONS: The inhibin B ≥58 pg/ml, LH ≥0.3 mIU/ml, FSH ≥0.5 IU/l or max LH ≥3.5 mIU/ml, max LH/FSH ≥1,0 on the GnRH agonist test, Δ testosterone ≥2.7 nmol/l on the hCG test have an excellent accuracy for the differential diagnosis of CDP and HH in prepubertal boys with delayed puberty.

Genes associated with testicular germ cell tumors and testicular dysgenesis in patients with testicular microlithiasis.

Testicular microlithiasis (TM) is one of the symptoms of testicular dysgenesis syndrome (TDS). TM is particularly interesting as an informative marker of testicular germ cell tumors (TGCTs). KIT ligand gene (KITLG), BCL2 antagonist/killer 1 (BAK1), and sprouty RTK signaling antagonist 4 (SPRY4) genes are associated with a high risk of TGCTs, whereas bone morphogenetic protein 7 gene (BMP7), transforming growth factor beta receptor 3 gene (TGFBR3), and homeobox D cluster genes (HOXD) are related to TDS. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, we investigated allele and genotype frequencies for KITLG (rs995030, rs1508595), SPRY4 (rs4624820, rs6897876), BAK1 (rs210138), BMP7 (rs388286), TGFBR3 (rs12082710), and HOXD (rs17198432) in 142 TGCT patients, 137 TM patients, and 153 fertile men (control group). We found significant differences in the KITLG GG_rs995030 genotype in TM (P = 0.01) and TGCT patients (P = 0.0005) compared with the control. We also revealed strong associations between KITLG_rs1508595 and TM (G allele, P = 0.003; GG genotype, P = 0.01) and between KITLG_rs1508595 and TGCTs (G allele, P = 0.0001; GG genotype, P = 0.0007). Moreover, there was a significant difference in BMP7_rs388286 between the TGCT group and the control (T allele, P = 0.00004; TT genotype, P = 0.00006) and between the TM group and the control (T allele, P = 0.04). HOXD also demonstrated a strong association with TGCTs (rs17198432 A allele, P = 0.0001; AA genotype, P = 0.001). Furthermore, significant differences were found between the TGCT group and the control in the BAK1_rs210138 G allele (P = 0.03) and the GG genotype (P = 0.01). KITLG and BMP7 genes, associated with the development of TGCTs, may also be related to TM. In summary, the KITLG GG_rs995030, GG_rs1508595, BMP7 TT_rs388286, HOXD AA_rs17198432, and BAK1 GG_rs210138 genotypes were associated with a high risk of TGCT development.