Term
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Definition
| A pattern of anomalies identified in two or more individuals but not yet identified as either a syndrome or sequence. |
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Term
| Chromosomal Abnormalities |
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Definition
Caused by abnormalities in the number or structure of chromosomes.
Problems in Number:
Monosomy: is an absence of an entire chromosome
Trisomy: extra chromosome
Partial trisomy: duplication of a piece of chromosome
Problems in Structure:
Deletion: absence of a piece of chromosome
Trans-location: exchange of materials between chromosomes belonging to different pairs
Inversion: rearrangement of genetic material on a single chromosome
Duplication: Small duplications occur frequently |
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Term
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Definition
| A single anomaly sets off a chain reaction of changes in the embryo which results in other anomalies. The primary defect may have several possible causes. There can be a malformation, deformation, disruption or dysplasia sequence. |
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Term
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Definition
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Term
| Morphogenesis: Deformation |
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Definition
| Abnormal form, shape, or position of a part of the body caused by mechanical forces (extrinsic). Roughly 80% self repair or sponaeous improve once the force is removed. deformations often occur secondary to malformations. |
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Term
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Definition
| Differentiation of cells and tissues om the embryo and fetus which establishes the form and structure of the various organs and parts of the body. This process is genetically controlled but vulnerable to environmental insult. |
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Term
| Types of Errors in Morphogenesis |
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Definition
| Malformation, Deformation, Disruption and Dysplasia |
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Term
| Morphogenesis: Malformation |
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Definition
| A defect in the formation of an organ, part of an organ, or large region of the body resulting from an intrinsically abnormal developmental process. Caused by an error in the earliest stage of formation (from the start). |
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Term
| Morphogenesis: Disruption |
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Definition
| A breakdown of previously normal tissues. Caused by an extrinsic force. |
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Term
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Definition
| A lack of normal organization of cells into tissue. An abnormal development of tissue (ie bones grow where tissue should be). |
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Term
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Definition
| The occurrence of multiple anomalies in a single individual where all anomalies are caused by a single primary agent (gene, chromosome or teratogen). Causes multiple defects in one or more tissues (Downs, Fetal Alcohol Syndrome) |
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Term
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Definition
| Congenital fissure of any part of the eye, especially of the iris. |
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Term
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Definition
| Caused by premature closure of sutures. The earlier it occurs the more profound the impact. Features are dependent on the which sutures close prematurely. |
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Term
| Ectrodactyl (Lobster Claw) |
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Definition
| "Split hand" and/or foot. Deep Clefts in anterior parts of the hand or foot. A rare deformity. Part of EEC syndrome (Ectrodactyl- Ectodermal Dysplasia- Cleft |
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Term
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Definition
| A dermoid cyst on the eyeball |
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Term
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Definition
| Congential deformity consisting of a vertical fold of skin on either side of the nose, sometimes covering the inner canthus. |
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Term
| Exophthalmos (aka. proptosis) |
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Definition
| abnormal protrusion of the eyeballs due to shallow orbits. |
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Term
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Definition
| A fistula is a pathologic tract between two cavities or between a physiologic cavity and the outside (ex. oronasal fistula). |
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Term
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Definition
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Term
| Lip Pits (lip mounds/ lip fistulae) |
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Definition
| Usually bilateral, symmertrically placed depressions or elevations on the vermillion of the lower lip, one on each side of the mid line. About 1/75,000 to 1/100,000. About 75% associated with CL/CP or CP. %0% recurrence risk for clefting |
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Term
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Definition
| Usually low set and slanted go together. Represents a lag in morphogenesis since the auricle is normally in that position in early fetal life. |
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Term
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Definition
| Small, deformed external ear; often associated with small/absent canal |
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Term
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Definition
| Asymmetry of the skull/cranium. Usually head tilts to one side and faces turns to the other side. Occurs with twisting of neck with unusual position of the head(torticollis). |
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Term
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Definition
| Ear tags. Tags of tissue situated anterior to the external ear. |
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Term
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Definition
| Band of tissue which bridges an incomplete cleft of the lip. About 10% of CL and/or CP have these. |
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Term
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Definition
| Union of fingers or toes. Fusion of bone or webbing of skins. Usually involves 3rd and 4th fingers/ 2nd and 3rd toes. |
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Term
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Definition
| Are genetic disorders but not inherited because most individuals with chromosomal disorders are not reproductively fit. |
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Term
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Definition
A locus on a chromosome. Has counterpart gene in matching location on paired gene except for male sex gene (XY).
Carries instructions regarding particular characteristics. They are strung along chromosomes like beads in a necklace. Mutant genes are abnormal genes. |
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Term
| Genetic Inheritance Types |
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Definition
Mendelian- 3 types
Autosomal Dominant
Autosomal Recessive
X Linked Recessive
X Linked Dominate |
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Term
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Definition
| Is the effect of a single mutant gene on an autosome. It is inherited from one parent while the gene from the other parent is normal. subsequent trait is transmitted through generations. 20% of syndromic clefts are autosomal dominant |
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Term
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Definition
| The affected individual has inherited a mutant gene from both parents. A normal gene is dominant so parent do not show the trait. Rare. 1/3 of syndromic clefts are autosomal recessive. |
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Term
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Definition
X linked traits are transmitted on the X chromosome. Manifestation is different for males and females because males only have on X chromosome and will express the trait because there is no normal counterpart gene. Females have two X chromosomes and normal genes on the other chromosome offsets the mutant
Usually only males are affected. 5% of syndromic clefts are X linked. |
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Term
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Definition
| Females show expression. Often lethal in males or very severe. |
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