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Fabry disease (FD) is a rare X-linked α-galactosidase A ( GLA ) deficiency, resulting in progressive lysosomal accumulation of globotriaosylceramide (Gb3) in a variety of cell types. Here, we report a novel splicing mutation (c.801 + 1G > A) that results in alternative splicing in GLA of a FD patient with variable phenotypic presentations of renal involvement. Sequencing of the RT-PCR products from the patient’s blood sample reveals a 36-nucleotide (nt) insertion exists at the junction between exons 5 and 6 of the GLA cDNA. Splicing assay indicates that the mutated minigene produces an alternatively spliced transcript which causes a frameshift resulting in an early termination of protein expression. Immunofluorescence shows puncta in cytoplasm for mutated GLA whereas uniform staining small dots evenly distributed inside cytoplasm for wild type GLA in transfected HeLa cells. The increased senescence and decreased GLA enzyme activity suggest that the abnormalities might be due to the altered localization which further might result from the lack of the C-terminal end of GLA. Our study reveals the pathogenesis of splicing mutation c.801 + 1G > A to FD and provides scientific foundation for accurate diagnosis and precise medical intervention for FD.

High soft tissue contrast resolution, acquisition of multi-planar images and the possibility to obtain functional information make magnetic resonance an interesting imaging technique to evaluate the small bowel disease. The absence of ionizing radiation is an important feature of magnetic resonance imaging (MRI) examinations because inflammatory diseases such as Crohn's disease (CD) are studied most frequently, which are prevalent among children and young adults. MRI, using modern equipment and a rigorous technical approach, can offer detailed morphologic information and functional data on the small bowel. This article discusses the MRI protocols for small bowel and the MR imaging findings of small bowel diseases, such as CD and small bowel neoplasms. There are two main approaches for MRI of the small bowel: (1) study following oral administration of contrast material; and (2) study with distension of lumen obtained with contrast material that is introduced through a naso-jejunal tube (MR enteroclysis). Oral contrast agents for small bowel MRIOral contrast agents can be classified into positive, negative and biphasic categories according to their action on the signal intensity of bowel lumen.A positive agent is a paramagnetic substance that produces a high signal intensity on T1-weighted sequences. It reduces T1 relaxation time without, or only minimally, influencing T2 relaxation time. Because of the water content of the contrast solution, it also results in high signal intensity on T2-weighted images. Positive contrast agents include paramagnetic substances, such as gadolinium chelates, ferrous and manganic ions and manganese ions [12][13][14][15][16] . The use of positive oral contrast agents has been abandoned almost completely because a hyperintense lumen does not enable a clear differentiation with inflammatory parietal enhancement.A negative agent is a substance that produces a low signal intensity on T1-and T2-weighted sequences. These substances induce local inhomogeneity in the magnetic field that affects T1 and T2 relaxation time. T2 effects predominate and are caused by spin dephasing with a consequent loss of signal intensity. Negative contrast agents include perfluorooctyl bromide [17] , iron oxides [15,18] , and oral magnetic particles [14,15] . Barium sulfate, if used at high concentrations, can be considered a negative contrast agent [19] . Negative contrast agents are more favorable if hyperintense signal of the bowel wall and the surrounding fat tissue signs of acute inflammation have to be detected on T2-weighted sequences [15] . However, magnetic susceptibility on gradient echo sequences may alter image quality on breath-held T1-weighted images.The term "biphasic" recently was introduced to define those substances that show different signal intensities depending on different sequences [20] . The first group (hyperintense signal on T1-weighted images and hypointense signal on T2-weighted images) included manganese and substances that contain manganese, and gadolinium chelates, w...

The variation in mutations in exons 3, 6, 7, 11 and 12 of the phenylalanine hydroxylase (PAH) gene was investigated in 59 children with phenylketonuria (PKU) and 100 normal children. Three single nucleotide polymorphisms were detected by sequence analysis. The mutational frequencies of cDNA 696, cDNA 735 and cDNA 1155 in patients were 96.2%, 76.1% and 7.6%, respectively, whereas in healthy children the corresponding frequencies were 97.0%, 77.3% and 8.3%. In addition, 81 mutations accounted for 61.0% of the mutant alleles. R111X, H64 > TfsX9 and S70 del accounted for 5.1%, 0.8% and 0.8% mutation of alleles in exon 3, whereas EX6-96A > G accounted for 10.2% mutation of alleles in exon 6. R243Q had the highest incidence in exon 7 (12.7%), followed by Ivs7 + 2 T > A (5.1%) and T278I (2.5%). G247V, R252Q, L255S, R261Q and E280K accounted for 0.8% while Y356X and V399V accounted for 5.9% and 5.1%, respectively, in exon 11. R413P and A434D accounted for 5.9% and 2.5%, respectively, in exon 12. Seventy-two variant alleles accounted for the 16 mutations observed here. The mutation characteristics and distributions demonstrated that EX6-96A > G and R243Q were the hot regions for mutations in the PAH gene in Shanxi patients with PKU.

Background Hearing impairment is one of most frequent birth defects, which affects nearly 1 in every 1,000 live births. However, the molecular etiology of non‐syndromic deafness in China is not well studied. Here, we have investigated the presence of mutations in three genes commonly mutated in non‐syndromic deafness patients in Shanxi Province, which has the highest frequency of birth defects in China. Methods In total, 1,201 unrelated non‐syndromic deafness patients and 300 healthy individuals were enrolled. The hearing ability was confirmed by audiologic evaluation. Three major deafness‐related genes ( GJB2, SLC26A4 (PDS), and mtDNA 12S rRNA ) of all individuals enrolled were analyzed by Sanger sequencing. Results The results showed that GJB2 mutations accounted for 21.23% (255/1,201) in the patient group, with c.235delC, a hotspot mutation, accounting for 10.99% (132/1,201). Moreover, 11 new GJB2 mutations were identified. SLC26A4 mutations accounted for 9.33% (112/1,201) in the patient group, with IVS7‐2A>G as the most prevalent mutation accounting for 4.75% (57/1,201). In addition, 15 patients (1.25%) were found to carry mtDNA 12S rRNA c.1555A>G mutation, while only two cases had the mtDNA 12S rRNA c.1494C>T. Conclusion In our research, it was found that c.235delC in GJB2 and c.919‐2A>G (IVS7‐2A>G) in SLC26A4 were the highest frequency pathogenic variants in Shanxi Province. Taken together, our data will enrich the database of deafness mutations and will help clinical diagnosis, treatment, and genetic counseling of hearing impairment.

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Autosomal recessive nonsyndromic hearing loss (ARNSHL) is a genetically heterogeneous neurosensory disorder, usually characterized by congenital or prelingual hearing loss. We report a Han Chinese male, born to consanguineous parents, presenting with nonsyndromic sensorineural hearing loss, whose clinical phenotype was also consistent with auditory neuropathy spectrum disorder (ANSD). After exome sequencing, a gap junction protein beta 2 gene (GJB2) c.235delC variant in the homozygous state was detected in the patient. Both parents were heterozygous for this variant, as documented by Sanger sequencing. The known pathogenic GJB2 c.235delC variant was not detected in 200 healthy controls. It is predicted to be a disease-causing alteration by generating a truncated protein p.(L79Cfs*3), disturbing the appropriate folding and/or oligomerization of connexins and leading to defective gap junction channels. This study shows that the association of homozygosity of the GJB2 c.235delC variant with ARNSHL and ANSD in a patient.