1Department of Endocrinology and Metabolism, National Research Institute for Child Health and Development, Tokyo 157-8535 and Departments of 2 Pediatrics and 3 Departments of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan
4 To whom correspondence should be addressed. Email: tomogata{at}nch.go.jp
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Abstract |
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Key words: fertility/FGFR1 mutation/genetic counselling/gonadotrophin therapy/Kallmann syndrome
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Introduction |
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Gonadotrophin therapy is frequently used to induce fertility. In particular, this therapy has been reported to be effective in HH including KS (Buchter et al., 1998), because it can directly compensate for the cause of infertility. This therapeutic intervention, however, may transmit the parental mutation to the next generation. The possibility is especially important in an autosomal dominant form of HH such as KS caused by FGFR1 mutations, because the transmission of a mutant allele can reproduce the same disease in the next generation.
To our knowledge, however, while such an effect and a risk are well predicted for the gonadotrophin therapy, there has been no report describing the transmission of mutant allele and resultant disease phenotype after gonadotrophin therapy. Here, we report on the effects and the consequences of gonadotrophin therapy in three KS families with FGFR1 mutations.
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Case reports |
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Family B
Proband (I-2), who married at 25 years of age, was referred to us because of primary amenorrhoea, and was found to have typical KS with HH and anosmia (Table I). She had no other phenotype described in KS. She was treated with conjugated estrogen (CE) (0.625 mg per os once per day) for the first 6 months and received cyclic HRT consisting of CE on days 114, CE plus medroxyprogesterone acetate (5 mg per os once per day) on days 1521, and no drug on days 2228 for the next 6 months. At that time, she had sufficient pubertal development (breast, Tanner stage 4; pubic hair, Tanner stage 3) and withdrawal bleeding. She hoped to have a child, and received gonadotrophin therapy with a regimen shown in Figure 2. At the second cycle of this regimen, she became pregnant, and delivered dizygotic twins by a Caesarean section at 35 weeks of gestation. Subsequently, gonadotrophin treatment was discontinued and HRT was re-started.
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Family C
Proband (II-1) was previously reported as a sporadic case with KS resulting from a heterozygous S107X mutation of FGFR1 at 11 years of age (Sato et al., 2004), and subsequent familial study disclosed an autosomal dominant form of KS. In brief, the proband was referred to us because of HH (peak LH value of 0.2 IU/l and FSH value of 0.1 IU/l in a GnRH test) and anosmia at 10 8/12 years of age. At 13 0/12 years of age, he exhibited no pubertal development, and clinical studies confirmed HH and olfactory dysfunction (Table I). To induce pubertal development, he was treated with TE with a gradual dosage increase from 25 mg to 200 mg i.m. per month. At 15 years of age, he manifested good pubertal development (genitalia, Tanner stage 4; pubic hair, Tanner stage 3), although his testes remained
1 ml in volume. He had no other KS features.
His younger sister (II-2) also came to us because of no pubertal development at 12 4/12 years of age. Endocrine results were suggestive of mild HH, while her olfactory function was apparently normal. She was placed on CE therapy, to induce pubertal development. She exhibited no other KS phenotype.
The mother (I-2) had a history of delayed puberty, oligomenorrhoea and hyposmia, although she had good pubertal development spontaneously. During the clinical examinations of the daughter, she confessed that she was seen at a local hospital because of infertility for 2 years after marriage at 25 years of age. Subsequently, her menses occurred at a frequency of six to eight times per year, and the measurement of basal body temperature indicated probable ovulation in roughly one-third of the cycles. She received gonadotrophin therapy with a regimen shown in Figure 2, under a provisional diagnosis of KS. At the second cycle of this regimen, she became pregnant and delivered the son (II-1) at 39 weeks of gestation. Three years later, she received the gonadotrophin therapy again and, consequently, she became pregnant in the third cycle of this regimen and gave birth to the daughter (II-2) at 40 weeks of gestation. Clinical assessment at 43 years of age, in conjunction with the history, indicated mild KS without other associated features (Table I). At that time, she still had oligomenorrhoea with a frequency of three or four times per year, although it was uncertain whether the cycles were associated with ovulation.
Molecular studies
This study has been approved by the Institutional Review Board Committees at National Center for Child Health and Development and Keio University Hospital. After obtaining written informed consent, leukocyte genomic DNA was amplified by PCR for all the coding region of FGFR1 (exons 218), and the PCR products were subjected to direct sequencing from both directions on a CEQ 8000 autosequencer (Beckman Coulter, Fullerton, CA, USA). The primer sequences and the PCR conditions have been described previously (Sato et al., 2004). To confirm heterozygous mutations, the corresponding PCR products were digested with appropriate restriction enzyme, or they were subcloned with TOPO TA Cloning Kit (Invitrogen, Carlsbad, CA, USA) and normal and mutant alleles were sequenced separately. For controls, leukocyte genomic DNA samples from 50 normal subjects were similarly analysed with permission.
Heterozygous FGFR1 mutations were identified in families AC. In family A, the proband (I-1) had a missense mutation at exon 17 (2233CT, P745S), and this mutation was present in the elder son (II-1) and absent in the younger son (II-2) (Figure 1). In family B, the proband (I-2) had a missense mutation at exon 16 (2059G
A, G687R), and this mutation was present in the female twin (II-2) and absent in the male twin (II-1) (Figure 2). In family C, a nonsense mutation at exon 3 (320C
A, S107X) was shared by the mother (I-2), the son (II-1), and the daughter (II-2) (Figure 2). These mutations were absent from 100 chromosomes of the 50 control subjects.
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Discussion |
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The gonadotrophin therapy successfully induced fertility in both male and female cases. This is consistent with the previous finding that the gonadotrophin therapy is effective in acquiring fertility in most patients with HH including KS (Aharoni et al., 1989; Buchter et al., 1998
; Kitahara et al., 1998
). In this context, FGFR1 mutation-positive patients with one normal allele might actually respond better to the gonadotrophin therapy, because some of them can have normal reproductive function (Dodé et al., 2003
). It should be pointed out, however, that not all disorders with HH respond to gonadotrophin therapy. It is known that male patients with mutant DAX1 (DSSAHC critical region on the X chromosome, gene 1) do not respond to the gonadotrophin therapy, although they have HH (Seminara et al., 1999
). This would primarily be due to the presence of primary as well as secondary testicular dysfunction in such patients (Seminara et al., 1999
). Indeed, DAX1 is expressed in gonads (Sertoli and interstitial cells) as well as adrenals, in addition to hypothalamus and pituitary (Ikeda et al., 2001
).
The gonadotrophin therapy resulted in the transmission of the mutant allele to the next generation. Furthermore, consistent with the dominant effect of FGFR1 mutations, mutation-positive children in families B and C showed clinically discernible KS phenotype. For the elder son of family A, it is uncertain whether he remains as an apparently non-manifesting carrier or exhibits KS phenotype such as defective pubertal development at a later age. Indeed, phenotypic spectrum is known to be variable in FGFR1 mutation-positive patients of both sexes, ranging from typical KS phenotype to apparently normal phenotype with intact olfactory and reproductive functions (Dodé et al., 2003). Taken together, the results actually demonstrate that gonadotrophin therapy in FGFR1 mutation-positive patients risks transmitting the mutation to the next generation and causing the KS phenotype in most, if not all, mutation-positive patients.
In addition to the effects and consequences of the gonadotrophin therapy, clinical variability in mutation-positive patients appears to be noteworthy (Table I). Several factors would be involved in the phenotypic diversity. First, there should be an influence of ascertainment bias. Indeed, the probands (I-1 in family A, I-2 in family B, and II-1 in family C) had typical KS phenotype, whereas other patients had mild or apparently normal phenotype. Second, sex difference may contribute to the phenotypic variability. In this regard, FGFR1 and anosmin-1 encoded by KALI are likely to interact in FGF signalling involved in the development of olfactory bulbs (the target regions in KS) (Dodé and Hardelin, 2004), and the local concentration of anosmin-1 should be higher in females than in males, because KALI partially escapes X-inactivation (Franco et al., 1991
; Legouis et al., 1991
). This would provide better FGF signalling in females than in males with heterozygous FGFR1 mutations, mitigating KS phenotype in affected females. Indeed, the phenotype was milder in the affected females than in the affected male in family C with the same mutation. In addition, the sex difference in the KALI dosage would explain why apparently the non-X linked form of KS is more prevalent in males than in females (Dodé and Hardelin, 2004
). Third, the type of mutations and other genetic and environmental factors would also be relevant to the clinical diversity. KS phenotype should be more severe in patients with amorphic mutations than in those with hypomorphic mutations, and haploinsufficiency of genes involved in human development frequently is known to show a wide range of penetrance and expressivity, probably depending on other genetic and environmental factors (Fisher and Scambler, 1994
). Such complexity would explain the lack of straightforward genotypephenotype correlations in affected individuals.
In summary, the results indicate that gonadotrophin therapy in FGFR1 mutations is effective in acquiring fertility but has a risk of transmitting the mutation and the disease phenotype to the next generation. Although the occurrence of such events is quite expected, this point should be considered in the application of gonadotrophin therapy and relevant genetic counselling.
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Acknowledgements |
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References |
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Buchter D, Behre HM, Kliesch S and Nieschlag E (1998) Pulsatile GnRH or human chorionic gonadotropin/human menopausal gonadotropin as effective treatment for men with hypogonadotropic hypogonadism: a review of 42 cases. Eur J Endocrinol 139, 298303.
Dodé C and Hardelin JP (2004) Kallmann syndrome: fibroblast growth factor signaling defect? J Mol Med 82, 725734.[CrossRef][ISI][Medline]
Dodé C, Levilliers J, Dupont JM, De Paepe A, Le Du N, Soussi-Yanicostas N, Coimbra RS, Delmaghani S, Compain-Nouaille S, Baverel F et al. (2003) Loss-of-function mutations in FGFR1 cause autosomal dominant Kallmann syndrome. Nat Genet 33, 463465.[CrossRef][ISI][Medline]
Fisher E and Scambler P (1994) Human haploinsufficiency: one for sorrow, two for joy. Nat Genet 7, 57.[CrossRef][ISI][Medline]
Franco B, Guioli S, Pragliola A, Incerti B, Bardoni B, Tonlorenzi R, Carrozzo R, Maestrini E, Pieretti M, Taillon-Miller P et al. (1991) A gene deleted in Kallmann's syndrome shares homology with neural cell adhesion and axonal path-finding molecules. Nature 353, 529536.[CrossRef][ISI][Medline]
Furukawa M, Kamide M, Miwa T and Umeda R (1988) Significance of intravenous olfaction test using thiamine propyldisulfide (Alinamin) in olfactometry. Auris Nasus Larynx 15, 2531.[Medline]
Groth C and Lardelli M (2002) The structure and function of vertebrate fibroblast growth factor receptor 1. Int J Dev Biol 46, 393400.[ISI][Medline]
Hasegawa Y (2003) Normal range of GnRH stimulation test. In Hasegawa Y (ed.) Let's Enjoy Pediatric Endocrinology, 3rd. Sindan-to-tiryou-sha, Tokyo, Japan, pp. 260262, (in Japanese).
Ikeda Y, Takeda Y, Shikayama T, Mukai T, Hisano S and Morohashi KI (2001) Comparative localization of Dax-1 and Ad4BP/SF-1 during development of the hypothalamic-pituitary- gonadal axis suggests their closely related and distinct functions. Dev Dyn 220, 363376.[CrossRef][ISI][Medline]
Japan Public Health Association (1996) Normal Biochemical Values in Japanese Children. Sanko Press, Tokyo, Japan, (in Japanese).
Kallmann FJ, Schoenfeld WA and Barrera SE (1944) The genetic aspects of primary eunuchoidism. Am J Ment Defic 48, 203236.
Kitahara S, Yoshida K, Ishizaka K, Higashi Y, Takagi K and Oshima H (1998) Secondary treatment failure without anti-human chorionic gonadotropin antibody in a patient with Kallmann syndrome. Int J Urol 5, 398400.[Medline]
Legouis R, Hardelin JP, Levilliers J, Claverie JM, Compain S, Wunderle V, Millasseau P, Le Paslier D, Cohen D, Caterina D et al. (1991) The candidate gene for the X-linked Kallmann syndrome encodes a protein related to adhesion molecules. Cell 67, 423435.[CrossRef][ISI][Medline]
Matsuo N (1993) Skeletal and sexual maturation in Japanese children. Clin Pediatr Endocrinol 2 (Suppl), 14.
Mayston MJ, Harrison LM, Quinton R, Stephens JA, Krams M and Bouloux PM (1997) Mirror movements in X-linked Kallmann's syndrome. I. A neurophysiological study. Brain 120, 11991216.[Abstract]
Murata M, Matsuo N, Tanaka T, Ohtsuki F, Ashizawa K, Tatara Y, Anzo M, Satoh M, Matsuoka H et al. (1993) Radiographic Atlas of Skeletal Development for the Japanese. Kanehara Press, Tokyo, Japan, (in Japanese).
Sato N, Katsumata N, Kagami M, Hasegawa T, Hori N, Kawakita S, Minowada S, Shimotsuka A, Shishiba Y, Yokozawa M et al. (2004) Clinical assessment and mutation analysis of Kallmann syndrome 1 (KAL1) and fibroblast growth factor receptor 1 (FGFR1, or KAL2) in five families and 18 sporadic patients. J Clin Endocrinol Metab 89, 10791088.
Seminara SB, Achermann JC, Genel M, Jameson JL and Crowley WF Jr (1999) X-linked adrenal hypoplasia congenita: a mutation in DAX1 expands the phenotypic spectrum in males and females. J Clin Endocrinol Metab 84, 45014509.
Suwa S, Tachibana K and Maesaka H (1992) Tanaka T and Yokoya S Longitudinal standards for height and height velocity for Japanese children from birth to maturity. Clin Pediatr Endocrinol 1, 513.
Submitted on December 26, 2004; resubmitted on February 24, 2005; accepted on April 7, 2005.
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