Introduction:
Aniridia (OMIM 106210) is a Panocular developmental malformation with complete or partial Iris hypoplasia being major feature of spectrum.(1) The prevalence of Aniridia (AN) is 1:40,000 to 1:100,000 without any known predilections for sex or gender.(1-3) The spectrum involves not only iris, but also the cornea, lens, optic nerve and fovea.(4)
AN can be familial with Autosomal Dominant Inheritance (AD) in two third of cases, while sporadic in rest of the patients. It can occur as an Isolated Ocular malformation without any systemic involvement or as part of Wilms tumor, Aniridia, Genital Anomalies, Retardation (WAGR) syndrome.(4, 5) AN results from mutations in the Paired Box gene-6 (PAX-6) located on chromosome 11p13, which encodes a highly conserved transcriptional regulator with two DNA binding and a transcriptional trans-activation domain.(6, 7) It is essential for oculogenesis, Central Nervous System (CNS), olfactory system(7) and endocrine glands.(8) Further, it plays multiple roles in development of the cornea, iris, lens and retina during ocular morphogenesis(7, 8) by regulating PAX6 itself, PAX2 , SRY -box 2 (SOX2) gene and a series of retinal transcription factors and structural proteins including crystallins of lens.(9-13) The PAX6 database currently documents 826 total variants and 357 unique DNA sequence changes.(14) Documented mutations in PAX6 include Premature Termination Codon (PTC), C-terminal extensions (CTE) and missense mutations.(14, 15)
Aniridia may be the initial manifestation of WAGR syndrome where deletion of (Wilms tumor 1) WT1 gene deletion in chromosome 11p13 gives rise to the phenotype.(16) WAGR syndrome results from a constitutional complete or partial deletion of 11p13 leading to conc...
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...6 haploinsufficiency causes cerebral malformation and olfactory dysfunction in humans. Nature genetics. 2001;28(3):214-6. Epub 2001/06/30.
29. Netland PA, Scott ML, Boyle JWt, Lauderdale JD. Ocular and systemic findings in a survey of aniridia subjects. Journal of AAPOS : the official publication of the American Association for Pediatric Ophthalmology and Strabismus / American Association for Pediatric Ophthalmology and Strabismus. 2011;15(6):562-6. Epub 2011/12/14.
30. Defreyn A, Maugery J, Chabrier S, Coullet J. [Gillespie syndrome: an uncommon presentation of congenital aniridia]. Journal francais d'ophtalmologie. 2007;30(1):e1. Epub 2007/02/09. Syndrome de Gillespie: un cas rare d'aniridie congenitale.
31. Roy FH. Aniridia, Cerebellar Ataxia, and Mental Deficiency (Gillespie Syndrome). Ocular Syndromes and Systemic Diseases. 4th ed. USA: MedRounds; 2007. p. 18.
ACHONDROPLASIA is known as being undersized, or less than 50in. in height. Having short limbs, a normal sized trunk, large head with a depressed nasal bridge and small face. This is a result of a disease in the thyroid gland. It can also be caused by Down syndrome or absorption, a cartilaginous tissue during the fetal stage. Hypochondroplasia, a mild form of dwarfism. Spinal tuberculosis and the deficiency of the pituitary gland secretions. Treatment with thyroxin or thyroid extract early in childhood results in normal growth and development. Somatrophin, also known as the human growth hormone is secreted by the anterior pituitary. Respiratory problems start to occur in infants. Symptoms of problems include snoring and sleeping with neck in a hyperextended condition. The limbs have rhizometic shortening. The legs are straight in infantry but when a child. He begins walking they develop a knock-knee position. When the child continues to walk legs begin to have a bowed-leg look. Occasionally, these curvatures are fixed. As the child continues to walk the kyphosis disappears and the back assumes a lordotic posture. If a delay in child’s walking occurs, the spine should be monitored closely for signs of gibbous formation. In infancy, hypercephalus can occur. Infants head circumference should be monitored close . Monthly checks of head circumference must be monitored. Radiologic studies are indicated if head circumference raises to disproportionately, or if symptoms of hydrocephalus. Child’s pediatrician should have a copy of head circumference curves for children with achondroplasia. Radiologic procedures for dwarfism include head ultrasound, C-T scan, or MRI of the head. If intervention is necessary, a ventriculoperitoneal shunt is placed relieving the pressure. Infants should also be monitored for foramen magnum compression. It is the opening at the base of the skull in which the brain stem and cervical spinal cord exit. When you have achondroplasia the foramen magnum is compressing the brain stem and spinal cord. Symptoms of narrowing include apnea the cessation of breathing and cervical myleopathy. C-T scans and MRI scans are done to examine the size of the infectious foramen magnum. A neurosurgical procedure called a foramen magnum decompression is executed to alarge foramen and alleviate further symptoms. Adolescents are at risk of getting lumbosacral spinal stenosis. The lumber spinal cord or nerve roots become compressed producing nerosurgical symptoms. Initial symptoms including weakness, tingling, and pain of the legs. Pain usually alleviated by assuming a squatting position.
To the medical doctor, Arnold-Chiari Malformation, which may have a genetic link, is characterized by a small or misshapen posterior fossa (the depression in the back of the skull), a reduction in cerebrospinal fluid pathways and a protrusion of the cerebellar tonsils through the bottom of the skull (foramen magnum) into the spinal canal resulting in a multitude of sensory-motor problems and even some autonomous malfunctions (1). These many symptoms can come in a variety of forms which often makes a clinical diagnosis difficult. To the patient this disorder can present not only physical difficulties but also mental distress. Treatment options and their success rates vary widely, and proponents of the cause are demanding more recognition, research, and success. The study of Arnold-Chiari malformations can lead to additional questions and new understandings about the I-function, sensory-motor input/output paths and the general make-up of the brain and nervous system, but a complete understanding of the disorder may be a long time coming.
Kish, Stephen J. et al : Brain Amino Acid Abnormalities in Dominantly Inherited Olivopontocerebellar Atrophy. Revised manuscript in preparation for resubmission to J. Neurochemistry.
Optometrists have accepted vision therapy, which is a medical treatment for optical muscle disabilities, as a feasible treatment used for eye related problems; claiming the treatment can strengthen vision and give the patient the opportunity to understand visuals quicker and clearer (Press). Vision therapy originated in the 1950s and over the past 25 years, has gained popularity, mainly because of new technological innovations in the field of treatment. Generally, vision therapy is prescribed as a measure mainly for people between the ages of 3 and 18. With the results from a comprehensive series of eye tests, the optometrist can work with the patient using special instruments—prisms, filters, occluders, and eye lenses—and strengthen the eye muscles, thus improving sight. According to optometrists in favor of vision therapy, these methods of treatment using these instruments function as safer routes to repair eye disabilities. Although vision therapy can yield favorable results, the practice as a treatment for innate eye disabilities has been in hot debate lately; as it can exceed $8000 and insurance companies do not cover the treatment. For decades, insurance companies have refused to accept vision therapy as a legitimate method for repairing eyesight (Boink). Concomitant with lack of insurance, the cost for a full treatment can exceed $8000, and doctors cannot guarantee a successful outcome. Recently, parents of children with eye related disabilities, such as amblyopia (lazy eye) and strabismus (cross-eye), and doctors have attempted to cooperate with public schools to allow families access to school-funded doctors to practice vision therapy. With a tight budget, most schools cannot afford to supply vision therapy, and a...
The cerebellum is usually associated with motor movements. Concerning this topic it is interesting to note the research of Dr. Eric Courchesne. He found that the VI and VII lobes of the cerebellum were smaller in autistics than those of a normal brain. This condition is called hypoplasia. The reverse condition, which is what Piven encountered, is called hyperplasia. Courchesne linked the cerebellum with attention shifting . He proposed that the autistic takes longer time to change the focus of his attention. He believed that this condition was caused by lack of development of the cerebellum in utero caused by perhaps oxygen deprivation, infection, toxic exposure, or genetically.
Ivy is the third generation in her family to be affected by achondroplasia. Her grandfather, her father, and her brother also have it. Achondroplasia is inherited as an autosomal dominant trait whereby only a single copy of the abnormal gene is required to cause achondroplasia. Nobody with the mutated gene can escape having achondroplasia. Many individuals with achondroplasia have normal parents, though. In this case, the genetic disorder would be caused by a de novo gene mutation. De novo gene mutations are associated with advanced paternal age, often defined as over age 35 years. If an individual with achondroplasia produce offspring with a normal individual, the chances of the offspring inheriting the mutant allele achondroplasia is 50%. If both of the parents have achondroplasia, the chances that their offspring will be of normal stature a...
This Child exhibits Angelman syndrome because of the tongue thrusting, small head size, and the crossing of eyes that is present in this picture. There are many different symptoms for Angelman Syndrome such as, seizures, usually beginning between 2 and 3 ...
Waardenburg Syndrome is a rare genetic disorder meaning that is caused by a mutation of genes. The disorder is classified as type I, II, III, or IV based on inheritance pattern and symptoms (Genetics 2013). Waardenburg Syndrome is an incurable disorder that is inherited from either one or both parents. If it came from one parent, it is an autosomal dominant pattern and if it came from both, it is known as an autosomal recessive pattern (Calendar 2013). Hearing loss, abnormalities with pigmentation of hair, eyes, and skin and other minor defects are some symptoms of Waardenburg Syndrome. There are many ways to diagnose the disorder and many treatments of the symptoms of it as well.
Duane Syndrome is an inherited unusual type of strabismus (squint) most often described by the incapability of the eye(s) to move inwards, outwards individually or together. This was first reported via ophthalmologists Jakob Stilling in 1887 and also Siegmund Türk in 1896. The syndrome was named after Alexander Duane, who explained the disorder more specifically in 1905. The syndrome is described as a miswiring of the eye muscles, causing eye muscles to tighten when they don’t need to and other eye muscles not to tighten when they need to. Very often patients get the syndrome by the age of 10 and it is more common in females (60% of the cases) than males (40% of the cases). Although the eye is usually the abnormality associated with Duane Syndrome, there are other bodily functions that can be affected. Duane syndrome cannot be cured, because the cranial nerve is missing and it cannot be replaced. The gene known as “SALL4” has been associated as a cause of this condition.
Wolf-Hirschhorn syndrome (WHS), first described by Wolf et al[1] and Hirschhorn et al[2], results from the hemizygous deletion of the distal short arm of chromosome 4. Due to the complex and unmarked expression of this disorder, the WHS syndrome is presumed to be a contiguous gene syndrome with an indeterminate number of genes responsible for the phenotype i.e. a multigenic etiology. [3][4]
In 1993 a consortium of researchers who worked on the DNA samples from families in the Lake Maracaibo region of Venezuela, an area with a high density of HD and significant consanguinity, reported the successful discovery of the gene responsible for the occurrence of this disease, present in chromosome 4 and named it as IT15 (Interesting transcript #15). IT15 later called as the Huntingtin gene (HTT) [2]. HTT is ~10 kilobases (kb) long and translated into a protein of 3144 amino acids with anticipated molecular mass of 348 kDa. Huntigtin protein is expressed in in human and all mammalian cells, where brain and testis has the highest concentration; liver...
Lewis, Ricki, (2014), Human Genetics, 11th Edition, Chapter 12. Gene Mutation. [VitalSource Bookshelf Online]. Retrieved from
There's a disease that lurks among young children even to this day. It's a direct result of a mutation in the genes that could result in the removal of the eye. Both boys and girls are affected, and one in every fifteen to thirty thousand babies is infected every year (Ambramson, Ch1). This eye corrupting, chromosomal abnormality shows up in about 300-350 new cases each year. It is called retinoblastoma.
Amblyopia is a condition in which visual acuity in one eye is greatly reduced. It is caused by lack of stimulation or disuse during visual development (Rose, 1998). Because the eye is not fully developed at birth (Jarvis, 1992, as cited in Rose, 1998), infants need stimulation to complete the visual neural pathway. When one or both eyes are inhibited, for example due to misalignment of one eye (strabismus) or a large difference in refractive power between two eyes (anisometropia), the neural pathway for the inhibited eye develops abnormally, or does not develop at all. At approximately six years of age eye development is complete (Stager, 1990, as cited in Rose, 1998). Before visual development is complete amblyopia can be treated. If it is caught and treated at an early age, normal vision can be preserved (Rose, 1998).
Wistow, G. J., and J. Piatigorsky. 1988. Lens crystallins: the evolution and expression of proteins for a highly specialized tissue. Annu. Rev. Biochem. 57: 479-504.