Dataset Information

Novel IFT140 variants cause spermatogenic dysfunction in humans.

ABSTRACT:

Background

The intraflagellar transport protein 140 homolog (IFT140) is involved in the process of intraflagellar transport (IFT), a process that is essential for the formation and maintenance of most eukaryotic cilia and flagella. Variants IFT140 have been reported to account for ciliopathy but association with male fertility has never been described in humans. Here we report the identification of two novel variants of IFT140 which caused spermatogenic dysfunction and male infertility.

Methods

Whole-exome sequencing was performed in a 27-year-old infertile man presented with severe oligozoospermia, asthenozoospermia, and teratozoospermia (OAT) without other physical abnormality. Sanger sequencing was used to verify gene variants in the patient, his healthy brother, and their parents. Morphology and protein expression in the patient's sperm were examined by transmission electron microscopy (TEM) and immunofluorescence staining. Function of gene variants was predicted by online databases.

Results

Compound heterozygous variants of IFT140: exon16: c.1837G > A: p.Asp613Asn and exon31: c.4247G > A: p.Ser1416Asn were identified in the patient, both of which showed autosomal recessive inheritance in his family, and had extremely low allele frequency in the population. Morphological abnormalities of the head, nucleus, and tails and the absence of IFT140 from the neck and mid-piece of the patient's spermatozoa were observed. Mutation Taster database predicted a high probability of damage-causing by both variations.

Conclusion

This study for the first time reported IFT140 variants that cause infertility in humans.

SUBMITTER: Wang X

PROVIDER: S-EPMC6732298 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature

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Publications

Novel IFT140 variants cause spermatogenic dysfunction in humans.

Wang Xiong X Sha Yan-Wei YW Wang Wen-Ting WT Cui Yuan-Qing YQ Chen Jie J Yan Wei W Hou Xiao-Tao XT Mei Li-Bin LB Yu Cui-Cui CC Wang Jiahui J

Molecular genetics & genomic medicine 20190808 9

<h4>Background</h4>The intraflagellar transport protein 140 homolog (IFT140) is involved in the process of intraflagellar transport (IFT), a process that is essential for the formation and maintenance of most eukaryotic cilia and flagella. Variants IFT140 have been reported to account for ciliopathy but association with male fertility has never been described in humans. Here we report the identification of two novel variants of IFT140 which caused spermatogenic dysfunction and male infertility.< ...[more]

PMID: 31397098

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Project description:Ciliopathies are rare congenital disorders, caused by defects in the cilium, that cover a broad clinical spectrum. A subgroup of ciliopathies showing significant phenotypic overlap are known as skeletal ciliopathies and include Jeune asphyxiating thoracic dysplasia (JATD), Mainzer-Saldino syndrome (MZSDS), cranioectodermal dysplasia (CED), and short-rib polydactyly (SRP). Ciliopathies are heterogeneous disorders with >187 associated genes, of which some genes are described to cause more than one ciliopathy phenotype. Both the clinical and molecular overlap make accurate diagnosing of these disorders challenging. We describe two unrelated Polish patients presenting with a skeletal ciliopathy who share the same compound heterozygous variants in IFT140 (NM_014,714.4) r.2765_2768del; p.(Tyr923Leufs*28) and exon 27-30 duplication; p.(Tyr1152_Thr1394dup). Apart from overlapping clinical symptoms the patients also show phenotypic differences; patient 1 showed more resemblance to a Mainzer-Saldino syndrome (MZSDS) phenotype, while patient 2 was more similar to the phenotype of cranioectodermal dysplasia (CED). In addition, functional testing in patient-derived fibroblasts revealed a distinct cilium phenotyps for each patient, and strikingly, the cilium phenotype of CED-like patient 2 resembled that of known CED patients. Besides two variants in IFT140, in depth exome analysis of ciliopathy associated genes revealed a likely-pathogenic heterozygous variant in INTU for patient 2 that possibly affects the same IFT-A complex to which IFT140 belongs and thereby could add to the phenotype of patient 2. Taken together, by combining genetic data, functional test results, and clinical findings we were able to accurately diagnose patient 1 with "IFT140-related ciliopathy with MZSDS-like features" and patient 2 with "IFT140-related ciliopathy with CED-like features". This study emphasizes that identical variants in one ciliopathy associated gene can lead to a variable ciliopathy phenotype and that an in depth and integrated analysis of clinical, molecular and functional data is necessary to accurately diagnose ciliopathy patients.

Project description:BackgroundAutosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disorder, characterized by development and enlargement of kidney cysts, eventually leading to end-stage kidney disease (ESKD). Pathogenic variants in the PKD1 and PKD2 genes are the major cause of ADPKD; additional rare variants in the GANAB, DNAJB11, ALG5 and ALG9 genes have been found in a minority of ADPKD patients. More recently, a significant number of ADPKD families have been linked to monoallelic variants in the IFT140 gene.MethodsIn this retrospective study, we tested the prevalence of the known causative genes of ADPKD-spectrum phenotype, including the PKD1, PKD2, GANAB, DNAJB11, ALG5, ALG and IFT140 genes, in a cohort of 129 ADPKD patients who consecutively underwent genetic testing in a single centre in Italy. Genetic testing utilized a combination of targeted next-generation sequencing, long-range polymerase chain reaction, Sanger sequencing and multiplex ligation-dependent probe amplification. Clinical evaluation was conducted through renal function testing and imaging features, including ultrasonography, computer tomography and magnetic resonance imaging.ResultsOf the 129 enrolled patients, 86 (66.7%) had pathogenic variants in PKD1 and 28 (21.7%) in PKD2, loss of function pathogenic variants in the IFT140 gene were found in 3 unrelated patients (2.3%), no pathogenic variants were found in other ADPKD genes and 12 patients (9.3%) remained genetically unresolved (ADPKD-GUR). Familial clinical and genetic screening of the index patients with ADPKD due to an IFT140 pathogenic variant (ADPKD-IFT140) allowed identification of eight additional affected relatives. In the 11 ADPKD-IFT140 patients, the renal phenotype was characterized by mild and late-onset PKD, with large renal cysts and limited kidney insufficiency. Extrarenal manifestations, including liver cysts, were rarely seen.ConclusionOur data suggest the monoallelic pathogenic IFT140 variants are the third most common cause of the ADPKD-spectrum phenotype in Italy, usually associated with a mild and atypical renal cystic disease.

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Dataset Information

Novel IFT140 variants cause spermatogenic dysfunction in humans.

Background

Methods

Results

Conclusion

Publications

Novel IFT140 variants cause spermatogenic dysfunction in humans.

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