Humans ; Kallmann Syndrome/genetics* ; Mutation, Missense ; Mutation

Kallmann syndrome (KS) is a clinically and genetically heterogeneous disorder that occurs in either an inherited or a sporadic manner. KS results from failed embryonic migration of GnRH-1 neurons from the nasal placode to the hypothalamus, due to the abnormal development of olfactory nerves and bulbs. Hypogonadotropic hypogonadism is related to GnRH deficiency, and anosmia is associated with the absence or hypoplasia of olfactory bulbs and tracts. KS patients can also present some non-reproductive or non-olfactory anomalies in addition to the above typical symptoms. For the high complexity of the molecular genetic mechanism of KS, to date, only 6 KS-related genes have been identified. The KAL1 gene is responsible for the X chromosome-linked recessive form of KS, while the fibroblast growth factor receptor 1 (FGFR1/KAL2) and fibroblast growth factor 8 (FGF8/KAL6) genes are related to the autosomal dominant form of the disease. However, the mutations in these 6 genes account for only about 25 - 30% of all KS cases, which suggests that other pathogenic genes involved in KS remain to be discovered. This article presents an overview on the studies of the pathogenic genes, clinical diagnosis and treatment of KS.
Extracellular Matrix Proteins ; genetics ; Humans ; Kallmann Syndrome ; genetics ; Mutation ; Nerve Tissue Proteins ; genetics ; Receptor, Fibroblast Growth Factor, Type 1 ; genetics

OBJECTIVE: To explore the etiology of a patient with Kallmann syndrome (congenital hypogonadism and anosmia) and a 45,X/46,XY karyotype. METHODS: Peripheral venous blood samples were collected from the proband and his parents and subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing. RESULTS: The proband was found to harbor compound heterozygous variants of the PROKR2 gene, namely c.533G>C (p.W178S) and c.308C>T (p.A103V), which were inherited from his father and mother, respectively. The two variants were respectively predicted to be likely pathogenic and variant of unknown significance, respectively. CONCLUSION The reduced chromosomal mosaicism might have caused no particular clinical manifestations in this patient. For patients with features of Kallmann syndrome, genetic testing is conducive to early diagnosis and can provide a basis for genetic counseling and clinical treatment.
Humans ; Genetic Testing ; Hypogonadism/genetics* ; Kallmann Syndrome/genetics* ; Karyotype ; Mutation ; Exome Sequencing ; Chromosomes, Human, X/genetics* ; Chromosomes, Human, Y/genetics*

The transcription factor SOX10, as a major actor in the development of the neural crest, plays a key role in the maintenance of progenitor cell multipotency, lineage specification, and cell differentiation. Abnormalities of neural crest development in humans lead to a number of genetic diseases known as neurocristopathies or neural crest disorders. The mutation of SOX10 can cause Kallmann syndrome (KS), which is a clinically and genetically heterogeneous condition and defined by the association between anosmia and hypogonadotropic hypogonadism due to incomplete migration of neuroendocrine gonadotropin-releasing hormone (GnRH) cells along the olfactory, vomeronasal, and terminal nerves. Since then, there have been a number of related reports that mutation of SOX10 will lead to KS with deafness. This review focuses on the SOX10 gene and the advances in the diagnosis and genetic studies of KS with deafness caused by the mutatuin of SOX10.
Cell Differentiation ; Deafness ; genetics ; Gonadotropin-Releasing Hormone ; Humans ; Hypogonadism ; Kallmann Syndrome ; genetics ; Mutation ; genetics ; SOXE Transcription Factors ; genetics

OBJECTIVETo explore the pathogenesis of a patient featuring azoospermia and steroid sulfatase deficiency.

METHODSPolymerase chain reaction (PCR), G-banded karyotyping and Illumina Human CytoSNP-12 Beadchip analysis were conducted.

RESULTSSTS sites PCR showed that there was no deletion in the AZF zone. G-banding analysis indicated an unknown structural change in chromosome X, which was verified by single nucleotide polymorphism array (SNP array) as a 5.4 Mb deletion in Xp22.31-p22.33.

CONCLUSIONThe Xp22.31-p22.33 deletion probably underlies the Kallman syndrome and steroid sulfatase defect in the patient.

Adult ; Humans ; Ichthyosis, X-Linked ; genetics ; Kallmann Syndrome ; genetics ; Karyotyping ; Male ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide

Kallmann syndrome (KS) is a rare hereditary disease. It is characterized by hypogonadotrophic hypogonadism in association with anosmia or hyposmia. At present, three modes of inheritance and genes related to KS have been identified. This review focuses on the clinical diagnosis and advances in the studies of the pathogenesis gene for Kallmann syndrome.
Diagnosis, Differential ; Extracellular Matrix Proteins ; genetics ; Humans ; Kallmann Syndrome ; diagnosis ; genetics ; therapy ; Male ; Nerve Tissue Proteins ; genetics ; Rare Diseases ; Receptor, Fibroblast Growth Factor, Type 1 ; genetics

OBJECTIVETo summarize the clinical features of idiopathic hypogonadotropic hypogonadism (IHH) diagnosed during childhood, and detect mutations in KAL1 and FGFR1, acting as key clues for diagnoses.

METHODWe collected and analyzed clinical data of 21 cases (including demographic data, chief complaint, history of present illness, family history, physical examination, laboratory tests and imaging studies, etc.) diagnosed with IHH from December 2008 to February 2013. Polymerase chain reaction and gene sequencing was applied to detect mutations on KAL1 and FGFR1. Fifty healthy unrelated individuals were choosen as controls.

RESULTOf 21 patients with IHH, 19 were males and 2 females, they visited us initially from 8-17 years old, with an average of (13.58 ± 2.38) years old. Sixteen cases were KS patients (76%). One boy reported abnormal sense of smelling but having olfactory perfect picture on MRI; 2/19 male cases had no puberty when they were over 13-14 years old without abnormal external genitalia. 8/19 cases only had small penis, 8/19 had both of cryptorchidism and small penis, and the Case 2 also had hypospadias. One boy had cryptorchidism combined with a normal penis. Only 2 girls diagnosed as IHH who visited us because of no puberty signs when they were 13 and 16 years old, respectively. Other clinical manifestations included: one with gynecomastia, 2 had mental retardation, and one was deaf; one with high palatal arch; one with mirror-movement and one with left renal agenesis but normal renal function respectively. Laboratory tests showed that the basic testosterone (T) is low and with inappropriately low or normal gonadotropin hormones. The results of cases of standard human chorionic gonadotropin (HCG) test of 7 cases out of 19 male children's were normal (testosterone>1 100 ng/L), and another nine cases continued to complete the extended HCG test, and the testosterone levels of two of them (cases 6, 8) were still lower than 1 000 ng/L. Family history: the parents in 9/21 family had delayed puberty, involving only one parent in 6 families, involving both in 2 families and the other one was an uncle having micropenis with a child. Among these 21 cases, only one boy's father had hyposmia and his first emission age was 14-15 years. Eleven patients accompanied abnormal sense of smelling and the olfactory organ abnormalities on MRI, 4 had olfactory organ abnormalities on MRI while they had good smelling function self-reportedly. We got 15 samples (12 KS and 3 nIHH cases) to screen the mutation of KAL1 (14 exons) and FGFR1 (18 exons). A splicing mutation c.1062+1G>A in KAL1 is identified in case 17 with IHH. One novel heterozygous FGFR1 mutation, a single base deletion mutation on the exon 1 c.27delC is identified in case 14. This mutation causes the premature termination codons.

CONCLUSIONThis pilot research showed that IHH/KS diagnosis in children depends on clinical manifestation rather than gene analysis. Small penis or cryptorchidism, smelling abnormality and positive familial history may contribute to the KS/HH diagnosis. MRI of olfactory bulb acts as important proof for diagnosis of KS. Mutations in KAL1 and FGFR1 gene are not main causes of Kallmann syndrome.

Adolescent ; Child ; DNA Mutational Analysis ; Exons ; genetics ; Extracellular Matrix Proteins ; genetics ; Female ; Heterozygote ; Humans ; Hypogonadism ; diagnosis ; genetics ; Kallmann Syndrome ; genetics ; Male ; Mutation ; genetics ; Nerve Tissue Proteins ; genetics ; Olfaction Disorders ; Receptor, Fibroblast Growth Factor, Type 1 ; genetics ; Sexual Maturation

OBJECTIVETo analyze the mutation of the KAL1 gene in male patients with idiopathic hypogonadotropic hypogonadism (IHH).

METHODSWe analyzed the exon mutation of the KAL1 gene in 30 IHH patients using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) combined with the PCR product direct sequencing technique.

RESULTSThree cases of the KAL1 gene mutation were found among the total number of patients, including 1 case of nonsense mutation (c. 1270C > T,p. R424X), and 2 cases of frameshift mutation, (c. 279_280delAG,p. G94fs) and (c. 1886_1887delTT,p. L629fs).

CONCLUSIONOf the 3 cases of the KAL1 gene mutation we detected, 2 are new and 1 already reported in the literature. The results of our study have provided valuable information on the molecular genetics of the IHH syndrome.

Adolescent ; Adult ; Base Sequence ; Child ; DNA Mutational Analysis ; Exons ; Extracellular Matrix Proteins ; genetics ; Humans ; Hypogonadism ; genetics ; Kallmann Syndrome ; genetics ; Male ; Mutation ; Nerve Tissue Proteins ; genetics ; Polymorphism, Single-Stranded Conformational ; Young Adult

Isolated gonadotropin-releasing hormone (GnRH) deficiency, including Kallmann's syndrome (KS) and idiopathic hypogonadotropic hypogonadism (IHH), is a congenital disorder, which is characterized by a functional deficit in hypothalamic GnRH secretion. Despite recent advances in the understanding of the pathogenesis of the X-linked form of KS as the identification of the KAL gene (Xp22.3), the genetic basis of the sporadic form in female patients remains unclear. Although most searches for mutations in X chromosome have been reported in males, the newly recognized phenomenon of inheritance, such as genomic imprinting and uniparental disomy, raises the possibility of a female phenotype in the X- linked genetic defect. Here, the molecular study of the coding region of the KAL gene (exon 5 to 14) in 10 unrelated females with KS (n=6) or IHH (n=4) is reported. None of the subjects had familial histories of delayed puberty or hypogonadism. Samples from 4 healthy, unrelated female volunteers were used for identification of polymorphisms. PCR of the 10 exons of the KAL gene was performed on genomic DNA. The PCR products of the 10 exons were subject to single strand conformation polymorphism (SSCP) analysis to identify possible mutations. In an SSCP analysis of the amplified fragments (fragment size: 147 to 302bp), no mutations or polymorphisms were found in any of the 10 patients and 4 controls. In conclusion, it is unlikely that KAL gene mutations are a clinically significant cause of sporadic GnRH deficiency in female patients, indicating the existence of defects in unidentified genes that result in the expression of the phenotypes in females.
Adolescent ; Adult ; DNA Mutational Analysis ; Extracellular Matrix Proteins/*genetics ; Female ; Gonadorelin/*deficiency ; Human ; Kallmann Syndrome/*genetics/metabolism ; Nerve Tissue Proteins/*genetics ; Phenotype ; Polymorphism, Single-Stranded Conformational ; Support, Non-U.S. Gov't