MRCPsych Paper A1 Mock Examination 2: Questions
Melvyn WB Zhang, Cyrus SH Ho, Roger Ho, Ian H Treasaden, Basant K Puri in Get Through, 2016
Which of the following statements about the genetics of AN is correct? Heritability of AN is around 50%.Less than 5% of first-degree relatives are usually affected.Linkage genes on chromosome 3 have been found.The ratio for monozygotic (MZ) to dizygotic (DZ) concordance is around 56:5.Research has found the concordance rates for monozygotic twins to be the same as that for dizygotic twins.
Neurotrophic Action of VIP
Sami I. Said in Proinflammatory and Antiinflammatory Peptides, 2020
Interestingly, in a recent publication, Sreedharan and his colleagues (88) describe the structure, expression, and chromosomal localization of the VIP1 receptor gene. Their results localized the human gene to chromosome 3 (3p22), a region associated with small-cell lung cancer. Allele loss in the area 3p23-p21 has been linked to many types of cancer, including small-cell lung carcinoma, possibly due to the presence of a functional tumor-suppressor gene in the region (89,90). Sreedharan et al. (48) have demonstrated a high level of expression of the human VIP1 receptor gene in lung tissue and suggested analysis of this gene-associated polymorphism for the acquisition of further information on the role of VIP and its receptors in human cancer. The results of Sreedharan et al. indicate that VIP may suppress lung cancer proliferation through the VIP1 receptor. However, results by Usdin et al. (58) indicate that the hybrid antagonist, under certain conditions, does not recognize the VIP1 receptor, suggesting the involvement of another VIP receptor site in the tumor inhibition mediated by the hybrid antagonist, perhaps a PACAP-preferring receptor. Studies on other VIP receptor genes, as well as on PACAP receptor genes, are necessary to decipher the role of VIP in cancer propagation.
Tumours of the Temporal Bone
John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed in Paediatrics, The Ear, Skull Base, 2018
An association had been established between tumours of the endolymphatic sac and Von Hippel–Lindau (VHL) disease.24 This autosomal dominant condition predisposes the patient to a number of conditions, including haemangioblastoma of the cerebellum, angiomatous lesions of the retina and renal cell carcinoma. The gene for this condition has been identified in the short arm of chromosome 3 (3p25) and a mutated suppressor gene has also been identified in both abnormal and neoplastic tissues of patients suffering from this condition. Gaffey et al. 18 pointed out that 15% of patients with ELSTs are known to have VHL disease. A review of the literature published in 2012 indicated an earlier age at presentation with ELST in VHL disease (31.3 years versus 52.5 years) with a female preponderance (female-to-male ratio of 2: 1 for VHL disease patients versus 1: 1 for non-VHL disease patients) and propensity for bilateral ELSTs in VHL disease.26
Abnormal chromosomes identification using chromosomal microarray
Published in Journal of Obstetrics and Gynaecology, 2022
Yunfang Shi, Xiaozhou Li, Duan Ju, Yan Li, Xiuling Zhang, Ying Zhang
A 34-year-old multipara at a gestational age of 18 weeks was referred to our prenatal diagnosis centre for foetal evaluation. Her first child was 3 years old with mental retardation, facial dysmorphism and developmental delay. She had a spontaneous abortion in the first trimester previously. Nuchal translucency (NT) measurement and first trimester screening were within normal limits. Amniocentesis was performed at a gestational age of 20 weeks and foetal karyotype was 46,XX,der(3), which showed an unbalanced karyotype with extra chromosomal material in the short arm of chromosome 3. SNP-array from the amniotic fluid was performed to further analyse the additional materials of unknown origin. Subsequent SNP-array identified a deletion of approximately 8.4 Mb in chromosome 3p26.3p26.1 and a duplication of 19.7 Mb in chromosome 5q34q35.3. The deletion region contained 14 OMIM genes including ITPR1. The duplication region encompasses 99 OMIM genes including NKX2-5, MSX2 and NSD1. Based on SNP-array findings, the foetal karyotype was unbalanced. The derivative chromosome 3 with loss of the segment 3p26.3pter and gain of 5q34qter replaced a normal chromosome 3 (Figure 1, Table 1).
Detection of extrascleral extension in uveal melanoma with histopathological correlation
Published in Orbit, 2018
Christopher K. H Burris, Vasilios P Papastefanou, Caroline Thaung, Marie Restori, Amit K Arora, Mandeep S Sagoo, Victoria M. L. Cohen
Nine patients had posterior ESE. These patients had a median age of 79 years (mean 74.4, range 56–86) and most of the patients (7/9) were male. Seven out of nine patients had not received prior treatment. The intraocular tumors were predominantly isolated to the posterior pole (5/9), were large (5/9) or medium-sized (4/9), collar-stud shaped (6/9), and were all melanotic. B-scan ultrasound only detected the ESE in the case with the largest posterior extension (a 6 mm nodule, see Table 1B – Notes). The other cases of macroscopic and microscopic posterior ESE were first discovered intraoperatively (three during enucleation), or following microscopic examination (5). Histopathologically, 6/9 were spindle type with two cases of mixed type and only one case with epithelioid morphology. Cytogenetic analysis in this group was available for six cases. Chromosome 3 abnormalities were detected in 5/6 cases and chromosome 8 abnormalities in 5/6 cases.
The role of toll-like receptors (TLRs) in pan-cancer
Published in Annals of Medicine, 2022
Runzhi Huang, Zehui Sun, Shuyuan Xian, Dianwen Song, Zhengyan Chang, Penghui Yan, Jie Zhang, Huabin Yin, Zixuan Zheng, Peng Hu, Zhenyu Li, Dan Huang, Yihan Liu, Chenyang Jiang, Man Li, Siqi Li, Tong Meng, Daoke Yang, Zongqiang Huang
TLR9's performance, which is likewise a critical component of innate and adaptive immunity, is particularly notable in the overall analysis results. This gene is located on chromosome 3 at positions 52,221,080–52,226,163 and 52,255,096–52,273,183. In contrast to TLR4 and TLR7, TLR9 forms both monomers and homodimers on the membrane and functions as a nucleotide-sensing TLR. Unmethylated cytidine-phosphate-guanosine (CpG) motifs (CpG ODNs), a TLR9 agonist, can stimulate antitumor immunity by activating the NF-κB pathway [5,62–64], and increase tumour cell death via cell cycle S phase arrest triggered by phosphorylated CHK2 [65–69]. Additionally, TLR9's identification of DNA factions assists in initiating T lymphocyte, B lymphocyte, and dendritic cell proliferation, activation, survival, and antibody production [68–71].
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