Molecular analysis of KAL-1 in a series of Kallmann syndrome and normosmic idiopathic hypogonadotropic hypogonadism patients from Northwestern China

We conducted an analysis of the Kallmann syndrome 1 （KAL-1） genotype in 17 patients with Kallmann syndrome （KS）, 9 patients with normosmic idiopathic hypogonadotropic hypogonadism （nlHH） and 20 age-matched normal men in Northwestern China. To do this, we used multiplex PCR analysis with exon-flanking primers and automated sequencing techniques with peripheral blood DNA samples. Intragenic deletions were found at the KAL-1 locus in two KS patients. One case with an atrial septal defect exhibited an intragenic deletion of exon 6. Another KS patient with cryptorchidism had intragenic deletions of exons 5 and 6. For the nlHH patients, no abnormalities were observed in the exonic and flanking sequences of KAL-1. This report describes two intragenic deletions of KAL-1 in two KS patients and suggests that KAL-1 deletion might be more prevalent in KS patients with other congenital organ abnormalities than those described previously in other series from Northwestern China.

Idiopathic Hypogonadotropic Hypogonadism— An Update on the Aetiopathogenesis, Management of IHH in Both Males and Females—An Exhaustive Review

Methods: Asystematic literature search was performed using PUBMED for all English articles up to April 2014. Although this review mainly focuses on published human studies, it also draws attention to where future research should be directed based on animal studies. Results: Besides the 9 known mutations widely quoted for KS namely KAL1, Fibroblast growth factor 8 (FGF8), fibroblast growth factor receptor 1 (FGFR1), prokineticin 2 (PROK2), PROK receptor 2 (PROKR2), WDR11, heparin sulfate-6-O-Transferase (HS6T1), chromodomain helicase DNA binding protein 7 (CHD7) and semaphorin 3A (SEMA 3A), additional mutations in “FGF8 synexpression” group e.g., FGF 17, ILRD, DUSP 6, SPRY4 and FLRT3 have been shown to be involved in CHH, mostly KS besides SEMA 7A. Although traditionally division has been based on anosmic/normosnic criteria, further genes found to cause so called nIHH like Gonadotropin releasing hormone receptor (GNRHR). KISS1, TAC3, TACR3 have also been found to be associated with hyposmia on detailed testing on UPSIT and MRI for olfactory structures revealed absent OB. Further detailed examination of transcription factor genes have revealed involvement of HESX1, TSHZ1, AXL, SOX10 with a strong overlap of in transcription factors in development of septooptic dysplasia (SOD), combined pituitary hormone deficiency (CHPD) and KS. Treatment with rFSH/-hCG gives almost similar results to pulsatile GnRH therapy and should be based on cost factor, availability and in occasional cases specific treatment like kisspeptin therapy. Conclusions: Contrary to the traditional thinking, one shoud reconsider classifying cases of IHH simply on basis of anosmia/normosmia. Deafness calls for looking for mutations in Sox 10/CHD7/ILRD7 considering 38% association of former. Therapy should be individualized based on availability of pulsatile GnRH, cost factor and in recalcitrant cases kp therapy may be of use with kp mutations and NKB mutations.

Reversal of idiopathic hypogonadotropic hypogonadism： a cohort study in Chinese patients

Although idiopathic hypogonadotropic hypogonadism （IHH） has traditionally been viewed as a life-long disease caused by a deficiency of gonadotropin-releasing hormone neurons, a portion of patients may gradually regain normal reproductive axis function during hormonal replacement therapy. The predictive factors for potential IHH reversal are largely unknown. The aim of our study was to investigate the incidence and clinical features of IHH male patients who had reversed reproductive axis function. In this retrospective cohort study, male IHH patients were classified into a reversal group （n = 18） and a nonreversal group （n = 336）. Concentration of gonadotropins and testosterone, as well as testicle sizes and sperm counts, were determined. Of 354 IHH patients, 18 （5.1%） acquired normal reproductive function during treatment. The median age for reversal was 24 years old （range 21-34 years）. Compared with the nonreversal group, the reversible group had higher basal luteinizing hormone （LH） （1,0±0.7 IU 1-1 vs 0.4±0.4 IU 1-1, P 〈 0.05） and stimulated LH （28.3 ± 22.6 IU 1-1 vs 1.9 ±1.1 IU 1-1, P 〈 0.01） levels, as well as larger testicle size （5.1 ±2.6 ml vs 1.5± 0.3 ml, P〈 0.01）, at the initial visit. In summary, larger testicle size and higher stimulated LH concentrations are favorite parameters for reversal. Our finding suggests that reversible patients may retain partially active reproductive axis function at initial diagnosis.

Whole exome sequencing and trio analysis to broaden the variant spectrum of genes in idiopathic hypogonadotropic hypogonadism

Dozens of genes are associated with idiopathic hypogonadotropic hypogonadism(IHH)and an oligogenic etiology has been suggested.However,the associated genes may account for only approximately 50%cases.In addition,a genomic systematic pedigree analysis is still lacking.Here,we conducted whole exome sequencing(WES)on 18 unrelated men affected by IHH and their corresponding parents.Notably,one reported and 10 novel variants in eight known IHH causative genes(AXL,CCDC141,CHD7,DMXL2,FGFR1,PNPLA6,POLR3A,and PR0KR2),nine variants in nine recently reported candidate genes(DCAF17,DCC,EGF,IGSF10,NOTCH1,PDE3A,RELN,SLIT2,and TRAPPC9),and four variants in four novel candidate genes for IHH(CCDC88C,CDON,GADL1,and SPRED3)were identified in 77.8%(14/18)of IHH cases.Among them,eight(8/18,44.4%)cases carried more than one variant in IHH-related genes,supporting the oligogenic model.Interestingly,we found that those variants tended to be maternally inherited(maternal with n=17 vs paternal with n=7;P=0.028).Our further retrospective investigation of published reports replicated the maternal bias(maternal with n=46 i^s paternal with n=28;P=0.024).Our study extended a variant spectrum for IHH and provided the first evidence that women are probably more tolerant to variants of IHH-related genes than men.