Syndactyly Essay

Achondroplasia is when cartilage during development is not developed into bone, which results in dwarfism. This condition also characterized by short limbs is initiated by a gain of function mutation in the FGFR3 gene. This mutation is a point mutation. When this mutation occurs, the receptor of the FGF does not need the FGF signal to be activated. This causes the chondrocytes to stop dividing and start differentiating into cartilage prematurely and the bones fail to grow to their proper length, thus resulting in the short limbs that result from this mutation. (textbook) The FGFR3 gene encodes for the Fibroblast growth factor receptor 3 protein. Textbook

Achondroplasia (ACH) is the most common form of short-limb dwarfism occuring in 1 in 15,000 to 28,000 births and appears to be slightly more prevalent in females, but indiscriminent toward race (1-3). Evidence has been found in Egypt for cases of ACH dating back as far as 4500 B.C. (4). In simplest terms, ACH is a disease where the dwarfing of bones formed in the cartilage occurs (5). There are many features that accompany this disease including rhizomelic (proximal) shortening of the extremities, megalencephaly (enlarged brain), short stature, trident hand, and frontal bossing (prominent forehead) (1, 3, 4, 6-8). Expression of this gene at high levels is primarily found in cells of the nervous system and the cartilage rudiments and

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V1 cells, which can be subdivided by function into Renshaw cells, Ia and other inhibitory subtypes, project their axons ipsilaterally. Experiments in embryonic chick suggest that many of these cells synapse with motor neurons (Wenner et al., 1998), and that selectively ablating these cells removes the V1-motor neuron inhibitory contact. The well-documented Renshaw cells appear to require Foxd3 transcription factor for cell differentiation and development (Stam et al., 2012). V1 neurons extend to the dorsal portion of the lateral motor column and navigate a short distance. V2 neurons exist in a more lateral region, ventral to V1 cells, during development. They are ipsilateral, descending and have varying transmitter phenotypes depending on the subtype. Mib1 protein is a key factor in V2 differentiation; if Mib1 is affected in mice, improper cell specification occurs leading to altered cell fate (Kang et al., 2013). V3 neurons comprise many subtypes which migrate to different locations, and consequently project

The Muse or Terpsichore is considered one of the most mysterious and realistic pieces of art in the Carlos Museum on Emory's campus. The Muse is a statue of a woman who is made out of marble. The statue lacks arms which adds to its mystery. Moreover, the marble itself gives the statue a rich and elegant design. As for the usage, the statute was possibly used as a decoration for homes around Greece because the statue is small and portable compared to a human size statue. The statue also has the features of a goddess, which could of indicated that she was possibly used as a protection or luck charm as well. The goddess look comes from the facial expression and the pose, which adds to the statue’s power and leadership. The woman’s face is smooth and soft, which adds to its beauty. Moreover, the powerful features that makes the statue stand out are

Fragile X Syndrome (FXS) is a trinucleotide repeat expansion disorder where triple expansion is preventing expansion of the FMR1 gene. (Bagni, et al., 2012; “Fragile X syndrome”, 2017).” Regarding this, Jasaseelan and Tenebaum state that Fragile X syndrome was the first disorder found to relate to RNA regulation to

Witkop syndrome is manifested by defects in the nail plates of fingers and toes typically and hypodontia, with normal hair and sweat gland function. There is a pattern of missing teeth.8 Absent maxillary incisors, second molars, and maxillary canines are the most common missing teeth.9 Genetically, mutations in genes MSX-1, PAX9, PsITX2, LTBP3, WNT10A, EDA and EDARADD, AXIN2, and IKBKG have been found associated with oligodontia. Mutations in MSX-1 have been shown to be associated with Witkop’s syndrome.[10)

Mutations in Twist1 are the only responsible for this specific syndrome. The mutations so far observed lead to the production of truncated or non-functional TWIST protein. Saethre-Chotzen syndrome is caused by haploinsufficiency for the TWIST gene. For this reason the mouse model proposed for this syndrome is a Twist+/− heterozygous mouse.

Batter syndrome is inherited autosomal recessive thick ascending loop disorder that is characterized by following clinical features:

should cycle for a few weeks prior to introducing axolotls into their new home so filter bacteria develop (Look, 2007).

The study of observing Hox gene expression was undertaken because of the confusion of their function. At the time Hox genes were known to pattern the embryo in an anterior to posterior fashion. They also knew loss-of-function or gain-of-function mutations caused major developmental changes, but it was hard to distinguish the specific type of mutation (ex. anterior or posterior homeotic transformations). It was also thought at the time that Hox genes played a role in global patterning, for comparative studies showed the boundaries of these genes changed the class of vertebrae. The problem was that mutations only made minor skeletal changes, which contradicted their thoughts about global patterning. To answer their thoughts about Hox genes, Hox10 and Hox11 were experimented with. The findings of the study were that Hox genes actually are involved with global patterning of axial skeletons of mammals (Wellick and Capecchi, 2003).

More than 380 mutations in the NSD1 gene have been identified in people with Sotos syndrome. However, In the Japanese population, the most common genetic change leading to Sotos syndrome deletes genetic material from the region of chromosome 5 containing the NSD1 gene. In most other populations, mutations within the gene itself are more frequent. These mutations include insertions or deletions of a small amount of DNA and changes in single DNA base pairs that make up the gene. Most mutations prevent one copy of the NSD1 gene from making any protein or lead to the production of an abnormally small, nonfunctional version of the protein. Research suggests that a reduced amount of NSD1 protein disrupts the normal activity of genes involved in growth and development. However, it remains unclear exactly how a shortage of this protein during development leads to overgrowth, learning disabilities, and the other signs and symptoms of Sotos syndrome (Faravelli, 2005; Genetics Home Reference,

The Pax gene family encodes for highly conserved DNA-binding transcription factors that play a vital role in embryonic development. All Pax proteins have a paired-box, DNA-binding domain of 128 amino acids located at the amino-terminal end, and is very highly conserved in Drosophila melanogaster, human, and mouse genes (Mansouri et al. 1996). Each different paralogous Pax gene has a crucial role in D. melanogaster and vertebrate development in terms of morphogenesis, organogenesis, cell differentiation, and oncogenesis (Mansouri et al. 1996). However, in this paper, the importance of Pax6’s discovery, mutations, and signaling pathway will be emphasized. It is worthy to note that Pax6 does not operate in a hierarchical linear signaling pathway but instead, in a massive network with numerous feedback loops. It is impossible to cover all possible feedback loops; therefore, the focus of the signaling pathway will be on the lens placode.

The disorder is a syndrome that is found in newborns and children that consisted of osteoporosis with fractures and skeletal deformities (Mccance & Huether, 2014). Its classification is based on both inheritance and clinical findings. In the most severe form of this disorder, the child is usually stillborn or dies soon after birth, but some may survive into childhood. In its more severe forms the signs and symptoms are evident at birth because fractures and deformity have occurred in utero. The less severe forms may be evident until the child starts to walk. Clinical manifestations of this disease are osteoporosis and increased rate of fractures, possible bony deformation, triangular faces, possible vascular weakness, possible blue sclera, and poor dentition (McCance & Huether, 2014). The main errors in this disease is due to the synthesis of collagen, a triple helix that contains two matching alpha chains and one beta chain. Collagen is mostly present in bone, cartilage, eye tissue, skin, and the vascular system. The severity of this disorder phenotype along the related anomalies are primarily dependent on the severity of the genetic anomaly and the part of the triple helix that is affected (Greeley, et al., 2013). Moreover,

MSX1 is a muscle segment homeobox gene 1 is also known as Hox7. It is expressed in segmented striated muscles and the central nervous system. It is one of homeobox family, non-cluster Homeobox Gene, which showed an important role in the embryonic development of Drosophila. Homeobox genes isolated from Xenopus, mouse, and human. The function of these genes is regulation the gene expression.