Deletion 7q

Monosomy of the long arm of chromosome 7 is characterized by structural abnormalities of the face including a broad nasal bridge with a stubby nose, a large mouth with an everted lower lip and downturned corners, low-set and malformed ears, and skeletal abnormalities such as short hands and feet, clubfeet, and lobster-claw deformities. Hydrocephalus with cortical atrophy and or seizures may be evident. The specific features of the syndrome are a function of the missing portion of the long arm...

Duplication 10p

Duplication of the short arm of chromosome 10 causes mental and growth retardation. Craniofacial features include dolicho-cephaly, a narrow face, broad cheeks, high forehead, nose with a broad root and bulbous tip, thin lips, cleft lip or palate, fissured tongue, micrognathia, and small chin. Additional manifestations include cardiac and renal anomalies, hypoplastic or cystic lungs, and skeletal anomalies such as camptodactyly, scoliosis, and flexion deformities. Ophthalmic features include...

Duplication 2p

Partial trisomy of the short arm of chromosome 2 is characterized by craniofacial features including microcephaly, a prominent forehead and or glabella, short nose with a broad bridge and prominent tip, high-arched palate, micrognathia, pointed chin, and low-set and dysplastic ears cardiac and genitourinary malformations and skeletal or digital anomalies may be present. Ophthalmic features include hypertelorism, epicanthus, strabismus, narrow palpebral fissures, blepharoptosis and...

Duplication 15q

Duplication of long arm of chromosome 15 results in mental and postnatal growth retardation with microcephaly associated with craniofacial features including microdolichocephaly, prominent occiput, sloping forehead, large, low-set ears, prominent bulbous nose, long philtrum and a midline crease in the upper lip, high-arched palate, and micrognathia. Ophthalmic manifestations include downward slanting of the palpebral fissures, narrow palpebral fissures, epicanthus, strabismus, blepharoptosis,...

Basic Concepts Of Chromosomal Disease

Deoxyribonucleic acid (DNA) is the fundamental unit that directs the orchestration of cellular function and transmits traits from one generation to the next. It is a self-reproducing macromolecule that determines the composition of proteins within the cell. The gene is a sequence of DNA that encodes for a single, specific protein or regulates the expression of a gene just as the DNA is arranged as beads on a necklace, the genes (specific segments of DNA) are similarly aligned. The information...

Breaking the News The Role of the Physician

Ianet and Marc thought their life was as close to perfection as any family's life could be. Married for 8 years, they had one daughter, Missy, age 5, and Brian, age 3 months, their long-awaited son. At Brian's 3-month routine well-baby checkup, the pediatrician remarked that Brian might have strabismus because his eyes appeared to turn in and weren't working together, as Janet later described it. The pediatrician was very reassuring, however, and told Marc and Janet that he would like the baby...

Trisomy 18 Edwards Syndrome

Caracteristicas Sindrome Edwards

Trisomy 18, initially identified in 1960,83 causes serious birth defects including a low birth weight microcephaly a characteristic facies with fawnlike ears, micrognathia, high arched palate, a narrow bifrontal diameter, and prominent occiput hypertonicity poor muscle development hand flexion with overlapping of second and fifth fingers and limited hip abduction (Fig. 3-10). Rocker-bottom feet, webbing of toes, and dorsiflexion of a short great toe are common. Renal anomalies including...

Dermoids and Dermolipomas

Dermoids are choristomas (histologically normal tissue in an abnormal location) and are thought to represent arrest or inclusions of epidermal and connective tissues (surface ectoderm and neural crest cells). They may be associated with abnormal closure of the optic fissure. This collection of epidermal and connective tissue can occur at the limbus (limbal dermoid), in the conjunctiva (dermolipoma), and subcutaneously in and around the orbit. The most common location of subcutaneous periorbital...

Trisomy 21 Downs Syndrome

The most common trisomy among live births is chromosome 21 or Down's syndrome, deriving its eponym from Langdon Down, who first described the clinical features in 1866.79 Systemic findings include hypotonia brachycephaly a large protruding tongue small nose with a low, small bridge small, poorly defined ears short, thick neck stubby hands with a single palmar crease clinodactyly of fifth digit with hypoplasia of mid-digital phalanges short, stubby feet with a wide gap between first and second...

Tunica Vasculosa Lentis

Lens Fetal Eyes

The lens receives nutrition and blood supply from the hyaloid artery, a branch of the primitive ophthalmic artery. The hyaloid artery first enters the eye through the optic fissure see Fig. 1-12 and then becomes incorporated into the center of the optic nerve as the optic fissure closes. The hyaloid vessels form a network around the posterior lens capsule and then anastomose anteriorly with the network of vessels in the pupillary membrane Fig. 1-16 . The pupillary membrane consists of vessels...