FRAXE FMR2 AFF2 GeneProber™ AFF2-AJ31Dig1
- Known as:
- FRAXE FMR2 AFF2 GeneProber™ AFF2-AJ31Dig1
- Catalog number:
- 40-2054-41
- Category:
- -
- Supplier:
- Gene Link
- Gene target:
- FRAXE FMR2 AFF2 GeneProber™ AFF2-AJ31Dig1
Related genes to: FRAXE FMR2 AFF2 GeneProber™ AFF2-AJ31Dig1
- Gene:
- AFF2 NIH gene
- Name:
- AF4/FMR2 family member 2
- Previous symbol:
- FMR2
- Synonyms:
- FRAXE
- Chromosome:
- Xq28
- Locus Type:
- gene with protein product
- Date approved:
- 2005-06-27
- Date modifiied:
- 2019-03-26
- Gene:
- FRAXE NIH gene
- Name:
- fragile site, folic acid type, rare, fra(X)(q28) E
- Previous symbol:
- -
- Synonyms:
- -
- Chromosome:
- Xq28
- Locus Type:
- fragile site
- Date approved:
- 1992-08-24
- Date modifiied:
- 2005-02-25
Related products to: FRAXE FMR2 AFF2 GeneProber™ AFF2-AJ31Dig1
Related articles to: FRAXE FMR2 AFF2 GeneProber™ AFF2-AJ31Dig1
- FRAXE-associated intellectual developmental disorder (FRAXE-ID) is a rare X-linked condition resulting from disruption of the AFF2 gene, usually through expansion of more than 200 CCG repeats and subsequent hypermethylation. Despite an estimated incidence of 1 in 50,000 to 100,000 males, it remains underdiagnosed due to its variable and non-specific phenotype. This report presents the clinical and molecular findings of three unrelated young male patients diagnosed with FRAXE-ID. All exhibited global developmental delay, mild to moderate intellectual disability, and subtle dysmorphic features. Molecular testing confirmed full mutations in the AFF2 gene in all cases, with one patient demonstrating size mosaicism. Southern blot confirmed hypermethylation of expanded alleles. The mothers of all three patients were premutation carriers. These findings emphasize the non-syndromic and often overlooked nature of FRAXE-ID. Accurate diagnosis relies on specific molecular techniques, underscoring the importance of clinical awareness and targeted testing to ensure appropriate diagnosis, management, and genetic counselling. - Source: PubMed
Publication date: 2025/10/14
Nunes Isabel SerraAbreu MariaDa Silva Jorge DiogoGonzaga DianaJorge PaulaSantos RosárioSoares Ana RitaMarques Isabel - Developmental and epileptic encephalopathy 70 (DEE70) is an epileptic encephalopathy associated with multiple neurological abnormalities and global developmental delay, among other characteristics. It has recently been established that it is caused by a heterozygous variant of the PHACTR1 gene, with currently four cases reported in the literature. This article presents a case report of a patient with DEE70 with a heterozygous variant in the PHACTR1 gene, who also presents a hemizygous variant in the AFF2 gene, associated with FRAXE syndrome. A phenotypic comparison is made between this case and the four other previously reported cases with variants in the PHACTR1 gene. In addition, the possible participation of the PHACTR1 and AFF2 genes in the clinical characteristics of the individual is discussed. - Source: PubMed
Publication date: 2022/12/19
Suarez-Mendez Marlen LizethRamirez-Cheyne JulianArango-Aguirre AndresRojas-Ceron Christian AndresLópez-Alvarez DianaPachajoa-Londoño Harry Mauricio - Over 100 X-linked intellectual disability genes have been identified, with triplet repeat expansions at the FMR1 (FRAXA) and AFF2 (FRAXE) genes being the causative agent in two of them. The absence of FRAXE pathognomonic features hampers early recognition, delaying testing and molecular confirmation. Hence, our laboratory uses a multiplex PCR-based strategy to genotype both FRAXA and FRAXE. However, AFF2 expansions are missed giving rise to an uninformative result in around 20% of female samples. To rule out undetected expansions and confirm homozygosity Southern blot analysis is performed being labour- and resource-intensive. The aim of this study is to develop a timely and economic triplet-primed amplification (TP-PCR) screening strategy to size the AFF2 GCC repeat and accurately assess homozygosity as well as pinpoint multiplex-PCR false negatives in female samples. In order to achieve this, validation was performed in a cohort of 500 females with a previous uninformative FRAXE PCR result. Interestingly, the presence of a T > C SNP (rs868949662), contiguous to the GCC repetitive tract, allows triplet primer binding in two additional repeats, increasing the discrimination power of the TP-PCR assay in heterozygous and homozygous samples. Twelve alleles outside the normal range were recognized: eight intermediate and four premutated, which seems relevant considering the rarity of the AFF2 expansions. All genotypes are concordant with that obtained by Southern blotting, confirming this as a strict, reproducible and low-cost homozygosity screening strategy that enables the identification of small expanded alleles missed by the routine multiplex-PCR due to allele dropout. Overall, this assay is capable of spotting multiplex-PCR false negatives besides identifying alleles up to > 80 GCC repeats. Furthermore, the occurrence of intermediate repeat sizes with unexpected frequency, introduces new areas of clinical research in this cohort in understanding these less explored AFF2 repeat sizes and newly associated phenotypes. - Source: PubMed
Publication date: 2021/07/19
Silva CecíliaMaia NunoSantos FláviaRodrigues BárbaraMarques IsabelSantos RosárioJorge Paula - Moderate to hyper-expansion of trinucleotide repeats at the FRAXA and FRAXE fragile sites, with or without concurrent hypermethylation, has been associated with intellectual disability and other conditions. Unlike molecular diagnosis of FMR1 CGG repeat expansions in FRAXA, current detection of AFF2 CCG repeat expansions in FRAXE relies on low-throughput and otherwise inefficient techniques combining Southern blot analysis and PCR. A novel triplet-primed PCR assay was developed for simultaneous screening for trinucleotide repeat expansions at the FRAXA and FRAXE fragile sites, and was validated using archived clinical samples of known FMR1 and AFF2 genotypes. Population samples and FRAXE-affected samples were sequenced for the evaluation of variations in the AFF2 CCG repeat structure. The duplex assay accurately identified expansions at the FMR1 and AFF2 trinucleotide repeat loci. On Sanger sequencing of the AFF2 CCG repeat, the single-nucleotide polymorphism variant rs868914124(C) that effectively adds two CCG repeats at the 5'-end, was enriched in the Malay population and with short repeats (<11 CCGs), and was present in all six expanded AFF2 alleles of this study. All expanded AFF2 alleles contained multiple non-CCG interruptions toward the 5'-end of the repeat. A sensitive, robust, and rapid assay has been developed for the simultaneous detection of expansion mutations at the FMR1 and AFF2 trinucleotide repeat loci, simplifying screening for FRAXA- and FRAXE-associated disorders. - Source: PubMed
Publication date: 2021/06/07
Liu TimingWang Furene SCheah Felicia S HGu YanghongShaw MarieLaw Hai-YangTay Stacey K HLee Caroline GNelson David LGecz JozefChong Samuel S - Hemophilia B is an X-linked recessive disorder caused by mutations in the F9 on Xq27.1. Mainly males are affected but about 20% of female carriers have clotting factor IX activity below 0.40 IU/ml and bleeding problems. Fragile-X syndrome (FMR1) and FRAXE syndrome (AFF2) are well-known causes of X-linked recessive intellectual disability. Simultaneous deletion of both FMR1 and AFF2 in males results in severe intellectual disability. In females the phenotype is more variable. We report a 19-year-old female with severe intellectual disability and a long-standing bleeding history. - Source: PubMed
Publication date: 2018/09/27
Stoof Sara C MKersseboom Rogierde Vries Femke A TKruip Marieke J H AKievit Anneke J ALeebeek Frank W G