Paternal origin of FGFR2 mutations in sporadic cases of Crouzon syndrome and Pfeiffer syndrome

Crouzon syndrome and Pfeiffer syndrome are both autosomal dominant craniosynostotic disorders that can be caused by mutations in the fibroblast growth factor receptor 2 (FGFR2) gene. To determine the parental origin of these FGFR2 mutations, the amplification refractory mutation system (ARMS) was used. ARMS PCR primers were developed to recognize polymorphisms that could distinguish maternal and paternal alleles. A total of 4,374 bases between introns IIIa and 11 of the FGFR2 gene were sequenced and were assayed by heteroduplex analysis, to identify polymorphisms. Two polymorphisms (1333TA/TATA and 2710 C/T) were found and were used with two previously described polymorphisms, to screen a total of 41 families. Twenty-two of these families were shown to be informative (11 for Crouzon syndrome and 11 for Pfeiffer syndrome). Eleven different mutations in the 22 families were detected by either restriction digest or allele-specific oligonucleotide hybridization of ARMS PCR products. We molecularly proved the origin of these different mutations to be paternal for all informative cases analyzed (P=2. 4x10-7; 95% confidence limits 87%-100%). Advanced paternal age was noted for the fathers of patients with Crouzon syndrome or Pfeiffer syndrome, compared with the fathers of control individuals (34. 50+/-7.65 years vs. 30.45+/-1.28 years, P<.01). Our data on advanced paternal age corroborates and extends previous clinical evidence based on statistical analyses as well as additional reports of advanced paternal age associated with paternal origin of three sporadic mutations causing Apert syndrome (FGFR2) and achondroplasia (FGFR3). Our results suggest that older men either have accumulated or are more susceptible to a variety of germline mutations.     

Oculocutaneous Albinism Type 3 (OCA3): Analysis of Two Novel Mutations in <Emphasis Type="Italic">TYRP1</Emphasis> Gene in Two Chinese Patients

Oculocutaneous albinism (OCA) is a genetic disease characterized by the reduction or deficiency of melanin in eyes, skin, and hair. OCA exhibits genetic heterogeneity. Presently, there are four types of OCA named as OCA1, OCA2, OCA3, and OCA4. OCA3 is more common in African born blacks but rarely found in other ethnic populations. Our recent genotyping of patients with OCA of Chinese descent has identified two patients who were not OCA1, OCA2, or OCA4. Examination and analysis of the TYRP1 gene identified them to be having OCA3. PCR and DNA sequencing analysis found that the mutant TYPR1 alleles were present in each of the two patients, c.780-791del/c.1067G>A (p.R356Q) and c.625G>TT (p.G209LfsX1)/c.643C>T (p.H215Y). The c.780-791del and c.1067G>A mutations have been already reported. However, the c.625G>TT and c.643C>T mutations have not been previously reported and were found to be maternal and paternal mutations, respectively. Moreover, population screening and bioinformatic analysis were carried out to determine the effects of these two mutations which revealed that both the mutation were pathogenic. Based on the similar mild phenotype of these two patients, we suggest that OCA3 might be prevalent within the Chinese population.     

Eight novel CARD15 variants detected by DNA sequence analysis of the CARD15 gene in 111 patients with inflammatory bowel disease

We performed a limited DNA sequence analysis of the CARD15 gene in 89 patients with Crohn’s disease (CD), 19 patients with ulcerative colitis (UC), and three patients with indeterminate colitis (IC), who were heterozygous carriers of one of the common CARD15 mutations [c.2104C>T (p.R702W), c.2722G>C (p.G908R), or c.3019_3020insC (p.Leu1007fsX1008)], the c.2462+10A>C variant, or of a new amino acid substitution in the 3′-end of exon 4. CARD15 exons 4, 5, 6, 8, and 11 were amplified by PCR and completely sequenced, thereby theoretically covering 73.9% of the described CARD15 variants and 96.6% of the mutated alleles. Using this approach, eight novel amino acid substitutions [c.1171C>T (p.R391C), c.1387C>G (p.P463A), c.2138G>A (p.R713H), c.2278C>T (p.R760C), c.2368C>T (p.R790W), c.2371C>T (p.R791W), c.2475C>G (p.N825K), and c.2546C>T (p.A849V)] were detected in six CD and two IC patients, and one UC patient. A severe disease phenotype was observed especially in patients who are compound-heterozygous for a common and a novel CARD15 mutation.Schnitzler and Brand contributed equally     

Haplotype analyses, mechanism and evolution of common double mutants in the human LDL receptor gene

Familial hypercholesterolemia (FH), an autosomal dominant inherited disorder resulting in increased levels of circulating plasma low-density lipoprotein (LDL), tendon xanthomas and premature coronary artery disease (CAD), is caused by defects in the LDL receptor gene (LDLR). Three widespread LDLR alterations not causing FH (c.1061-8T>C, c.2177C>T and c.829G>A) and one mutation (c.12G>A) with narrow geographical distribution and thought to cause disease were investigated. In an attempt to improve knowledge on their origin, spread and possible selective effects, estimations of the ages of these variants (t generations) and haplotype analysis were performed by genotyping 86 healthy individuals and 98 FH patients in Spain for five LDLR SNPs: c.81T>C, c.1413G>A, c.1725C>T, c.1959T>C, and c.2232G>A; most patients carried two of these LDLR variants simultaneously. It was found that both the c.1061-8T>C (t = 54) and c.2177C>T alterations (t = 62) arose at about the same time (54 and 62 generations ago, respectively) in the CGCTG haplotype, while the c.12G>A mutation (t = 70) appeared in a CGCCG haplotype carrying an earlier c.829G>A alteration (t = 83). The estimated ages of selectively neutral alterations could explain their distribution by migrations. The origin of the c.12G>A mutation could be in the Iberian Peninsula; despite its estimated age, a low selective pressure could explain its conservation in Spain from where it could have spread to China and Mexico, since the sixteenth century through the Spanish/Portuguese colonial expeditions.     

Studies of type I collagen (<Emphasis Type="Italic">COL1A1</Emphasis>) α1 chain in patients with osteogenesis imperfecta

Nucleotide sequences of exon 51, adjacent intron areas, and regulatory region of the α1 chain of type I collagen (COL1A1) gene were analyzed in 41 patients with osteogenesis imperfecta (OI) from 33 families and their 68 relatives residing at Bashkortostan Republic (BR). Six mutations (four nonsense mutations c.967G>T (p.Gly323X), c.1081C>T (p.Arg361X), c.1243C>T (p.Arg415X), and c.2869C>T (p.Gln957X)) in patients of the Russian origin and two frameshift mutations (c.579delT (p.Gly194ValfsX71), and c.2444delG (p.Gly815AlafsX293)) in patients with OI of Tatar ethnicity as well as 14 single nucleotide polymorphisms in the COL1A1 gene were revealed. Mutations c.967G>T (p.Gly323X) and three alterations in the nucleotide sequence c.544-24C>T, c.643-36delT, and c.957 + 10insA were described for the first time.     

Changes in the connexin 26 gene (<Emphasis Type="Italic">GJB2</Emphasis>) in Russian patients with hearing loss: Results of long-term molecular diagnostics of hereditary nonsyndromic hearing loss

Molecular testing for mutations in the connexin 26 gene (GJB2) is a routine diagnostic analysis for subjects with hereditary hearing loss worldwide. However, till now there is no assessment of the diagnostic significance of this analysis for Russian patients, and there are difficulties in interpretation of the results of DNA diagnostics. In the present study, a sample of 705 patients with nonsyndromic autosomal recessive hearing loss from different regions of Russian Federation was investigated. A portion of DFNB1 hearing loss caused by mutations in the GJB2 gene among the sample was 46%. The frequency of DFNB1 hearing loss was 1:1000, that is, the frequency of isolated autosomal recessive hearing loss 1:500 in the population. It was found that each sixteenth individual in Russia is a heterozygous carrier of the mutation in the GJB2 gene. Totally, 20 pathological GJB2 alleles were detected; among them, a c.35delG mutation with the allelic frequency 81% prevails. Six most frequent mutations (c.35delG, c.313_326del14, c.23+1G>A (IVS1+1G>A), c.235delC, c.167delT, and p.Glu120del), which account for 95% of pathological GJB2 alleles, were detected. Mutations previously not described in the GJB2 gene (c.129delG, p.Gly200Arg, and c[Arg127His, Gly160Ser]) were found. An optimal algorithm of molecular testing of Russian patients which detects up to 100% of mutations in the GJB2 gene was suggested. Data concerning a clinical significance of p.Met34Thr and p.Val37Ile mutations are confirmed in the study. Eight polymorphic substitutions in the GJB2 gene which do not have clinical significance (p.Val27Ile, c.*3C>A, p.Val153Ile, p.Gly160Ser, c.Arg127His, p.Glu114Gly (c.341A>G), c.-45C>A, and p.Ala149Thr) were also detected.     

A neurodevelopmental disorder with a nonsense mutation in the Ox-2 antigen domain of the amyloid precursor protein (APP) gene

We report a patient, an infant with a neurodevelopmental disorder manifesting intractable complex partial epilepsy, bull's eye maculopathy, microcephaly, bilateral cataracts, truncal hypotonia, and spasticity of all four extremities. Sequencing of genomic DNA revealed mutations in (a) exon 8 (Ox-2 antigen domain) of the amyloid precursor protein (APP) gene: c.1075C>T, p.Arg359^* (b) exon 8 of the senataxin (SETX) gene: c.4738C>T, p.Arg1580Cys, and (c) exon 2 of the ceroid-lipofuscinosis, neuronal 8 (CLN8) gene: c.685C>G, p.Pro229Ala. Using a quantitative method for measurement of various APP-mRNA isoforms, we found that the APP-mRNA isoform of 624 bp with a deletion starting after 49 bp of the 5′ end of exon 3 followed by a complete deletion of exons 4–15, mutations in exon 1: c.22C>T, p.L18F, and exon 3: c.269A>G, p.Q90R encoding APP₂₀₇ isoform was the most abundant one, and would appear to be responsible for the clinical manifestations. This is the first example that may underline the role of the epigenetic regulation in the expression of APP gene leading to a neurodevelopmental disorder resulting from a nonsense mutation in the Ox-2 antigen domain.     

Genetic variants of <Emphasis Type="Italic">CYP1B1</Emphasis> and <Emphasis Type="Italic">WDR36</Emphasis> in the patients with primary congenital glaucoma and primary open angle glaucoma from saint-Petersburg

In 32 unrelated patients with primary congenital glaucoma (PCG), a search for mutations in the myocilin (MYOC), cytochrome P450B1 (CYP1B1), and WDR36 genes was performed. The Q368X mutation in myocilin gene, typical of the patients with adult-onset primary open-angle glaucoma (POAG), was not detected in the PCG patients. Screening of the CYP1B1 introns 2 and 3 for the presence of mutations in PCG patients revealed only six DNA polymorphisms, including IVS1-12ntT>C (g.3793 T>C), A119S (g.4160 G>T; GCC>TCC), G188G (g.4369 C>A; GGC>GGA), L432V (g.8131 C>G; CTG>GTG), D449D (g.8184 C>T; GAC>GAT), and N453S (g.8195 A>G; AAC>AGC) (nucleotide numbering is given in accordance with the GenBank sequence U56438). In the groups of PCG patients and donors without eye diseases, the frequencies of these variants were not statistically significantly different, pointing to the neutrality of these polymorphisms. Furthermore, the CYP1B1 polymorphism L432V, considered to be associated with POAG in some world populations, was not associated with this disease in the patients from St. Petersburg. DNA collections obtained from the POAG and PCG patients and from the control group were tested for the carriage of the worldwide distributed mutations of the WRD36 gene, D658G, R529Q, A449T, and N355S. D658G variant was found with equally low frequencies in the groups of POAG and PCG patients, as well as in the control group. Mutations A449T and R529Q were found only once each, while mutation N355S was not detected in any of the groups examined. Our results indicate that the WDR36 variants make no substantial contribution to the development of POAG and PCG in the patients from St. Petersburg and represent normal DNA polymorphism. It is likely that in most of the PCG patients from the population examined the disease is not associated with the CYP1B1 gene defects.     

Identification of single nucleotide polymorphisms in the bovine follicle‐stimulating hormone receptor and effects of genotypes on superovulatory response traits

In dairy cows, there is evidence that failure to respond to superovulation protocols is a heritable trait. In women, genotyping for the p.N680S single nucleotide polymorphism (SNP) in the follicle‐stimulating hormone receptor (FSHR) gene may help identify poor responders before ovarian stimulation is initiated. Our objectives were to identify SNPs in the coding region of the bovine FSHR gene and to investigate the effect of FSHR genotypes on superovulatory response in Holstein cattle. Sequencing of FSHR exons 1–10 revealed seven SNPs. Three were non‐synonymous mutations (c.337C>G, c.871A>G and c.1973C>G). SNP c.337C>G encodes for a proline‐to‐alanine (p.Pro113Ala) amino acid replacement in the extracellular ligand‐binding domain of the receptor. PCR‐RFLP analyses showed that homozygous GG Holstein cows present a higher percentage of viable embryos, whereas GG and CG animals have less unfertilised oocytes. SNP c.871A>G results in an isoleucine‐to‐valine (p.Ile291Val) modification, and homozygous AA animals present lower embryo yield after superovulatory treatments. SNP c.1973C>G corresponds to a threonine‐to‐serine (p.The658Ser) modification in the intracellular carboxyl‐terminal domain of the FSHR protein, and homozygous GG Holstein cows were associated with a lower embryo yield and a higher percentage of unfertilised oocytes. Our results suggest that specific alleles of the bovine FSHR gene are associated with variations in embryo yield and in the number of unfertilised oocytes.     

Novel Mutation in the <Emphasis Type="Italic">MECP2</Emphasis> Gene Identified in a Group of Rett Syndrome Patients from Ukraine

Mutations in the MECP2 gene are known to cause Rett syndrome (RTT)—a neurodevelopmental disorder, one of the most common causes of intellectual disability in females, with an incidence of 1 in 10000–15000. We have investigated exons 3 and 4 of the MECP2 gene, that coding MBD and TRD domains of the MeCP2 protein, in 21 RTT patients from Ukraine by PCR-DGGE analysis followed by Sanger sequencing of PCR fragments with abnormal migration profiles. In 13 of 21 (61.9%) patients 7 different mutations were identified one nonsense mutation—c. NC_000023.11:g.154031326G>A (MECP2:c.502C>T) and 4 missense mutation NC_000023.11:g.154031409G>T (MECP2:c.419C>T), NC_000023.11:g.154031355G>A (MECP2:c.473C>T), NC_000023.11:g.154031354A>C (MECP2:c.472A>C), NC_000023.11:g.154031431G>A (MECP2:c.397C>T) located in exon 4, a rare RTT-causing splice site mutation NC_000023.10:g.153296903T>G (MECP2:c.378-2A>C) in intron 3 and deletion NC_000023.10:g.1532 96079_153296122del44 in exon 4. The novel mutation MECP2:c.472A>C identified in our study in patients withclassic RTT phenotype leds to T158P substitution. It is one more confirmation of crucial role that 158 codon in MECP2 protein function.     

Mutations of <Emphasis Type="Italic">MC4R</Emphasis> gene and its association with economic traits in Qinchuan cattle

MC4R belongs to a seven-transmembrane G-protein-coupled receptor which may regulate body composition and insulin action. Many mutations in the MC4R gene are associated with obesity, energy expenditure and serum triglyceride levels in human and animals. Six mutations in the MC4R gene were identified in our study (-293C>G, -193A>T, -192T>G, -129A>G, -84T>C and 1,069C>G). The -129A>G was significantly associated with live weight (LW) (P < 0.05), Cattle with the genotypes AG and GG had higher LW than genotype AA. The 1,069C>G was significantly associated with LW, carcass weight (CW), backfat thickness and marbling score (MS). Cattle with the genotype GG had higher LW, CW and MS than genotype CC; Cattle with the genotypes GG and CG had higher MS than CC. The results suggested that -129A>G and 1,069C>G SNP of the MC4R gene may be useful as a genetic marker for carcass and meat quality traits in Qinchuan cattle.     

Missense mutations in the BMP15 gene are associated with ovarian failure

Premature ovarian failure (POF) is an unexplained amenorrhoea (>6 months) with raised levels of gonadotropins (FSH>40 U/L) occurring before the age of 40 years. Recent studies have elucidated the role of oocyte derived growth factors (BMP15 and GDF9) in maintenance of folliculogenesis, granulosa cell (GC) proliferation and overall fertility. Our recently published work showed presence of two rare missense variants in the GDF9 gene associated with ovarian failure (Dixit et al. 2005, Menopause 12:749–754). The present case-control study has been structured to establish the role of BMP15 germline status associated with ovarian failure. Sequence analysis of the coding region of the BMP15 gene was carried out in a cohort of women with POF (n=133), primary amenorrhoea (n=60), and secondary amenorrhoea (n=9) compared with control females (n=197). This study revealed a total of 18 germline variants in the coding region of BMP15 gene, including 16 novel variants. These novel variants include one intronic variant, one 3’ flanking variant, one silent variant, and 13 missense variants. Eleven missense variants were present only in cases with complete absence in the control females. The remaining two missense variants viz. c.308A>G (p.Asn103Ser) and c.788_789insTCT (p.Leu263_Arg264insLeu) were present both in the cases and in the controls. The c.788_789insTCT variant was significantly higher in primary amenorrhoea cases than in the controls (Fisher’s exact test, P=0.034). Three frequent variants c.-9C>G, c.308A>G, and c.852C>T were chosen for haplotyping. The haplotype G-G-C was found to be significantly associated with ovarian failure (P=0.0075). In a nutshell, the BMP15 gene is highly associated with etiology of ovarian failure.     

A novel mutation screening system for Ehlers-Danlos Syndrome, vascular type by high-resolution melting curve analysis in combination with small amplicon genotyping using genomic DNA

Ehlers-Danlos syndrome, vascular type (vEDS) (MIM #130050) is an autosomal dominant disorder caused by type III procollagen gene (COL3A1) mutations. Most COL3A1 mutations are detected by using total RNA from patient-derived fibroblasts, which requires an invasive skin biopsy. High-resolution melting curve analysis (hrMCA) has recently been developed as a post-PCR mutation scanning method which enables simple, rapid, cost-effective, and highly sensitive mutation screening of large genes. We established a hrMCA method to screen for COL3A1 mutations using genomic DNA. PCR primers pairs for COL3A1 (52 amplicons) were designed to cover all coding regions of the 52 exons, including the splicing sites. We used 15 DNA samples (8 validation samples and 7 samples of clinically suspected vEDS patients) in this study. The eight known COL3A1 mutations in validation samples were all successfully detected by the hrMCA. In addition, we identified five novel COL3A1 mutations, including one deletion (c.2187delA) and one nonsense mutation (c.2992C>T) that could not be determined by the conventional total RNA method. Furthermore, we established a small amplicon genotyping (SAG) method for detecting three high frequency coding-region SNPs (rs1800255:G>A, rs1801184:T>C, and rs2271683:A>G) in COL3A1 to differentiate mutations before sequencing. The use of hrMCA in combination with SAG from genomic DNA enables rapid detection of COL3A1 mutations with high efficiency and specificity. A better understanding of the genotype–phenotype correlation in COL3A1 using this method will lead to improve in diagnosis and treatment.     

Frequency of the allelic variant c.1150T > C in exon 10 of the fibroblast growth factor receptor 3 (FGFR3) gene is not increased in patients with pathogenic mutations and related chondrodysplasia phenotypes

Mutations in the FGFR3 gene cause the phenotypic spectrum of FGFR3 chondrodysplasias ranging from lethal forms to the milder phenotype seen in hypochondroplasia (Hch). The p.N540K mutation in the FGFR3 gene occurs in ∼70% of individuals with Hch, and nearly 30% of individuals with the Hch phenotype have no mutations in the FGFR3, which suggests genetic heterogeneity. The identification of a severe case of Hch associated with the typical mutation c.1620C > A and the occurrence of a c.1150T > C change that resulted in a p.F384L in exon 10, together with the suspicion that this second change could be a modulator of the phenotype, prompted us to investigate this hypothesis in a cohort of patients. An analysis of 48 patients with FGFR3 chondrodysplasia phenotypes and 330 healthy (control) individuals revealed no significant difference in the frequency of the C allele at the c.1150 position (p = 0.34). One patient carrying the combination `pathogenic mutation plus the allelic variant c.1150T > C’ had a typical achondroplasia (Ach) phenotype. In addition, three other patients with atypical phenotypes showed no association with the allelic variant. Together, these results do not support the hypothesis of a modulatory role for the c.1150T > C change in the FGFR3 gene.     

Deciphering the impact of somatic mutations in exon 20 and exon 9 of PIK3CA gene in breast tumors among Indian women through molecular dynamics approach

We examined 25 breast tumor samples for somatic mutations in exon 20 and exon 9 of PIK3CA gene in South Indian population. Genomic DNA was isolated and amplified for PIK3CA gene, followed by direct sequencing of purified polymerase chain reaction products. We identified PI3K3CA mutations in 5 of 25 (20%), including four of the mutations in p.H1047R and one in p.H1047L. Nucleotide base substitution A to G (c.3140A > G) and A to T (c.3140A > T) results in p.H1047R and p.H1047L mutation in exon 20 of PIK3CA gene. We did not observe any mutation in exon 9 of PIK3CA gene. Furthermore, we investigated the effect of mutations on protein structure and function by the combination of sequence and structure-based in silico prediction methods. This determined the underlying relationship between the mutation and its phenotypic effects. Next step, we complemented by molecular dynamics simulation analysis (30 ns) of native and mutant structures that measured the effect of mutation on protein structure. The obtained results support that the application of computational methods helps predict the biological significance of mutations.     

The CDKN2A/p16INK4a 5′UTR sequence and translational regulation: impact of novel variants predisposing to melanoma

Many variants of uncertain functional significance in cancer susceptibility genes lie in regulatory regions, and clarifying their association with disease risk poses significant challenges. We studied 17 germline variants (nine of which were novel) in the CDKN2A 5′UTR with independent approaches, which included mono and bicistronic reporter assays, Western blot of endogenous protein, and allelic representation after polysomal profiling to investigate their impact on CDKN2A mRNA translation regulation. Two of the novel variants (c.‐27del23, c.‐93‐91delAGG) were classified as causal mutations (score ≥3), along with the c.‐21C>T, c.‐34G>T, and c.‐56G>T, which had already been studied by a subset of assays. The novel c.‐42T>A as well as the previously described c.‐67G>C were classified as potential mutations (score 1 or 2). The remaining variants (c.‐14C>T, c.‐20A>G, c.‐25C>T+c.‐180G>A, c.‐30G>A, c.‐40C>T, c.‐45G>A, c.‐59C>G, c.‐87T>A, c.‐252A>T) were classified as neutral (score 0). In conclusion, we found evidence that nearly half of the variants found in this region had a negative impact on CDKN2A mRNA translation, supporting the hypothesis that 5′UTR can act as a cellular Internal Ribosome Entry Site (IRES) to modulate p16^INK4a translation.     

New mutation in the <Emphasis Type="Italic">MYOC</Emphasis> gene and its association with primary open-angle glaucoma in a Chinese family

Myocilin (MYOC) gene is expressed in many ocular tissues, including the trabecular meshwork, a specialized eye tissue essential in regulating intraocular pressure. Many mutations in MYOC have been detected in primary open-angle glaucoma (POAG). We investigated whether MYOC mutations contributed to the susceptibility to POAG in a Chinese family. In a four-generation family affected with POAG, ocular examinations were performed on all members of the pedigree to determine their disease status, and 200 healthy matched controls were recruited. PCR–restriction fragment length polymorphism (PCR–RFLP) analysis and DNA sequencing were used to determine the mutations in MYOC. Biological software was used to analyze the corresponding proteins for missense mutations. The c.1084G>− was found, for the first time, in four of eight affected patients and in one of two patients with suspected POAG. The c.1006C>T mutation was found in two of eight patients and in one of 19 subjects who were asymptomatic. The frequencies of c.1084G>− and c.1006C>T were 12.82 and 7.69%, respectively, in patients but not in the controls. These data provide additional clues to the pathogenesis of POAG because no other mutation was detected in either group. Our results suggest that the MYOC c.1084G>− may contribute to a genetic predisposition to POAG.     

aPCR-SSCP and DNA sequencing detecting two silent SNPs at KAP8.1 gene in the cashmere goat

Keratin-associated proteins 8.1 gene (KAP8.1) is a structural gene responsible for the cashmere. KAP8.1 protein contains high glycine and tyrosine, which concerns regulation and function of the matrix structure fiber. In this study, the polymorphism of KAP8.1 gene was detected by methods of aPCR-SSCP (asymmetric polymerase chain reaction single-strand conformation polymorphism) and DNA sequencing in 791 individuals from two breeds. The results showed that there were two mutations in this gene. The mutations were described as c.63 T>G and c.66 C>G, which would result in two synonymous mutations in KAP8.1 protein. The findings go against previous research, in which there was not polymorphism at KAP8.1 gene. The reasons might be that different cashmere breeds were detected in two studies. Further analysis of results leads us to believe that the polymorphism of KAP8.1 gene might be relevant to fiber diameter.