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Congenital hypothyroidism
Published in Pallavi Iyer, Herbert Chen, Thyroid and Parathyroid Disorders in Children, 2020
Thyroid dysplasia (TD) compromises 85% of cases of PH and includes complete agenesis (15–33% by scintigraphy), hemi-agenesis, hypoplasia, and ectopy (48–51% of TD by scintigraphy). Ectopy results from incomplete caudal migration of the primordial thyroid anlage from its locus near the base of the tongue to its final position anterior to the trachea. Ectopic remnant tissue is dysplastic and insufficient for postnatal thyroid hormone requirements. Genetic causes for TD are rarely identified but can include transcription factor mutations in the development of the thyroid gland and other tissues. Five monogenic causes of TD (with either autosomal dominant [AD] or recessive [AR] inheritance) are worth noting, (1) TSH receptor inactivating mutations, including G-protein signaling defects (AR), (2) NXK2-1 or brain-lung thyroid syndrome (AD), (3) PAX8 (AD), (4) FOXE-1 or Bamforth–Lazarus syndrome (AR), and (5) NKX2-5.
Regeneration of Cardiomyocytes from Bone Marrow Stem Cells and Application to Cell Transplantation Therapy
Published in Richard K. Burt, Alberto M. Marmont, Stem Cell Therapy for Autoimmune Disease, 2019
Various cardiac specific transcription factors have been cloned, and their genes are serially expressed in the developing heart during myogenesis and morphogenesis. Figure 4 shows the time course of the expression of cardiomyocyte-specific transcription factors in fetal developing heart and CMG cells. The genes coding Nkx2.515 (homeobox type transcription factor specifically expressed beginning in the early developing heart), GATA416 (GATA-motif-binding Zinc finger type transcription factor expressed beginning in the early stage developing heart), HAND 1/2 (basic helix-loop-helix type transcription factor expressed in the heart and autonomic nervous system), and MEF2-B/C17 (muscle enhancement factor: a MADS box family transcription factor expressed in the myocytes) were expressed in the early stage of heart development, and MEF2A and MEF2-D in the middle stage. The CMG cells already expressed GATA4, TEF-118(transcription enhancement factor 2), Nkx2.5, HAND, and MEF2-C before exposure to 5-azacytidine, and they expressed MEF2-A and MEF2-D after exposure to 5-azacytidine. This pattern of gene expression in CMG cells was similar to that of developing cardiomyocytes in vivo,11 and indicated that the developmental stage of the undifferentiated CMG cells is close to that of cardiomyoblasts or the early stages of heart development. We estimated that the stage of differentiation of the CMG cells lies between the cardiomyocyte-progenitor stage and the differentiated cardiomyocyte stage.
Individual conditions grouped according to the international nosology and classification of genetic skeletal disorders*
Published in Christine M Hall, Amaka C Offiah, Francesca Forzano, Mario Lituania, Michelle Fink, Deborah Krakow, Fetal and Perinatal Skeletal Dysplasias, 2012
Christine M Hall, Amaka C Offiah, Francesca Forzano, Mario Lituania, Michelle Fink, Deborah Krakow
Genetics: autosomal dominant, almost complete penetrance; mutations in the gene TBX5 can be found in roughly 70% of patients; in a few cases mutations in the gene SALL4 have been identified. TBX5 is a member of the T-box family of transcription factors and is involved in specification of cardiac and forelimb structures during embryogenesis. TBX5 interacts with NKX2.5 and GATA4 in regulating cardiogenesis, particularly in cardiac septation, and is involved in the development of the cardiac conduction system. SALL4 encodes the sal-like protein 4, which contains 3 C2H2 double zinc finger domains of the SAL-type. Sal-like protein 4 is essential for the development of the epiblast and primitive endoderm from the inner embryonic cell mass. It interacts with SALL1 in anorectal, heart, brain and renal development and with TBX5 in patterning and morphogenesis of the first digit of the upper limbs. Other conditions caused by mutations in SALL4 are Duane radial ray syndrome and acro-renal-ocular syndrome (AROS).
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).
A comprehensive review of cardiotoxic effects of selected plants
Published in Toxin Reviews, 2021
Akbar Anaeigoudari, Nahid Azdaki, Mohammad Reza Khazdair
Li et al. (2019) also investigated the effects of paeoniflorin (the main chemical ingredient in herbaceous peony) against carditoxicity effects of aconitine on h9c2 cells. The results indicated a significant increase in cell proliferation, Bcl-2/Bax ratio, up-regulation of p53 level, reduction of caspase 3 and decrement of intracellular malondialdehyde (MDA) and extracellular lactate dehydrogenase (LDH) in paeoniflorin treated group compared to aconitine group. While there was not any significant difference in intracellular superoxide dismutase (SOD) between two groups (Li et al.2019). It has been reported that aconitine (2.5 μg/L) caused a deficient cardiovascular system with yolk sac hemorrhage and early cardiac dysfunctions in embryonic zebrafish. It also decreased the expression of cardiac genes such as, Tbx5, Gata4, and Nkx2.5 in the early stage of embryo (Liu et al.2019).
Congenital extremity anomalies with a TBX5 pathogenic variant in consecutive IVF assisted pregnancies: a case report of Holt-Oram Syndrome
Published in Journal of Obstetrics and Gynaecology, 2022
Omar Sobh, Robert O’Sullivan, Maurice J. Mahoney, Gary Kleinman
Holt-Oram Syndrome is caused by haploinsufficiency of the TBX5 gene. This gene encodes for a transcription factor, T-box 5, which activates genes involved in the development of the upper limbs, cardiac septum, and cardiac conduction system (Basson et al. 1997; Gros and Tabin 2014). TBX5 is a transcription factor that promotes cardiomyocyte differentiation by associating with NKX2-5 (Hiroi et al. 2001). In approximately 26% of cases, molecular analysis does not identify a variant in TBX5. This may suggest variation in the noncoding or regulatory regions associated with TBX5 or genetic heterogeneity that is not yet recognised (McDermott et al. 2005).