CH 19: Genetic and Developmental Diseases and Disorders: Human Diseases 4th edition

s. Genetic disorders are passed to offspring in four ways:

(1) autosomal dominant, (2) autosomal recessive, (3) sex-linked dominant, or (4) sexlinked recessive.

The nucleus of each cell of the normal body has _____chromosomes or _____ pairs of chromosomes.

46 or 23

____________ is an opening between the right and left atria commonly due to the foramen ovale not closing at birth. Atrial septal defects allow oxygenated blood to be pumped from the left atria to the right atria. This repumping causes an increased workload on the right side of the heart.

Atrial septal defect

_____________________, is a severe type of developmental disorder characterized by a preoccupation with inner thoughts, daydreams, fantasies, and delusions. The cause of autism is unknown, although there may be a physical cause. Treatment is varied but behavioural therapy is always employed.

Autism, also called autistic disorder

______________is a congenital bilateral paralysis that results from inadequate blood or oxygen supply to the brain during fetal development, the birthing process, or infancy. The disorder usually affects motor, or muscle, performance. It is the most common crippler of children. It is characterized by hyperactive reflexes, rapid muscle contraction, and weakness

Cerebral palsy

__________ and _________consists of one or more splits in the upper lip and palate. This anomaly leads to difficulty in feeding and, if not repaired, in speaking. Several surgeries may be necessary to completely correct the condition

Cleft lip and palate

________________ is a stricture or narrowing that causes high blood pressure proximal to the stricture and lower blood pressure distal to the stricture. This increases the heart's workload.

Coarctation of the aorta

________________ (CHD) is an abnormality of the hip joint resulting in the femoral head slipping out of the normal position. It is usually obvious in the first few months of life

Congenital hip dislocation

____________________ is the transmission of the rubella virus across the placenta to the fetus. This may cause spontaneous abortion or an infant with birth defects. Prevention includes immunization against rubella.

Congenital rubella syndrome

_________________is an abnormal congenital opening of the male urinary meatus under the surface of the penis.

Hypospadias

____________ genes are expressed with a capital letter and ___________ genes are expressed with a small letter

Dominant and recessive

The most common autosomal chromosomal disorder is ________

Down syndrome

________________ (Trisomy 21) is the condition of having 3 chromosomes instead of the normal 2 in the 21st position of the chromosome chain.

Down syndrome

______________________include mild to severe intellectual disability, abnormal facial features (flat nasal bridge, low-set ears, slanted eyes with epicanthus, and thick tongue), abnormally short extremities, and organ defects. Down syndrome is the most common cause of genetic intellectual disability.

Down syndrome

The most common type of muscular dystrophy is_____________________. It is a sex-linked disorder passed from mother to son

Duchenne's MD

______________________ is an abnormal opening of the meatus on top of the penis

Epispadias

________ (sex cells) also have 46 chromosomes, but reproduce differently.

Germ cells

______________is caused by the absence of nerves in a segment of the colon. Without nerves, the affected segment lacks peristalsis, causing massive distention of the colon with feces. Treatment is surgical removal of the affected segment

Hirschsprung's disease

__________________ is an abnormal accumulation of cerebrospinal fluid in the brain. It is usually caused by obstruction of the flow of cerebrospinal fluid due to congenital defect, infection, or tumors. The head of the affected child enlarges as the fluid accumulates. This causes abnormal development and intellectual disability.

Hydrocephalus

____________ is caused by a chromosomal disorder in which affected males have an extra X chromosome (XXY), rather than the normal XY

Klinefelter's syndrome

The affected muscles are unable to store protein, so the muscle fibers die and are replaced by fat and connective tissue. Over time, the muscle goes from weak to useless.

MD

an outpouching of the ileum

Meckel's diverticulum

Developmental malformations include;

Meckel's diverticulum, esophageal atresia, congenital diaphragmatic hernia, imperforate anus

______________________is a group of genetically inherited diseases characterized by degeneration or weakening of the muscles.

Muscular dystrophy (MD)

CHD Diagnosis is confirmed by physical examination, a positive ___________and x-ray

Ortolani's sign,

______________________________ is an inherited condition characterized by abnormally brittle bones, leading to frequent fractures. There is no cure for the disorder, but the tendency to fracture decreases with age

Osteogenesis imperfecta

___________________ is a connection between the pulmonary artery and the aorta of the normal fetal heart that should close at birth. In this condition, oxygenated blood is shunted from the aorta back to the pulmonary artery

Patent ductus arteriosus

____________________is a recessive genetic disorder leading to faulty metabolism of the protein phenylalanine, which builds up in the blood and becomes present in the urine. It is toxic to the brain cells and causes intellectual disability. Diagnosis is made by mandatory PKU testing at birth

Phenylketonuria (PKU)

_____________ is a narrowing of the outlet of the lower end of the stomach. It is caused by a thickening of the pyloric sphincter. This slows the emptying of the stomach and may cause vomiting

Pyloric stenosis

Genetic and developmental disorders may first appear or be diagnosed at

any age

commonly due to the foramen ovale not closing at birth

atrial septal defect

_____________ is a congenital disorder in which one or more of the vertebra of the spinal column fails to close over the spinal cord, leaving an opening

Spina bifida

In disorders such as___________________genetic testing can inform an individual if he/she is a carrier of the disease.

Tay-Sachs disease,

_______________________________ an autosomal recessive disorder of lipid metabolism

Tay-Sachs disease,

_________________________ is a combination of four defects including pulmonary valve stenosis, right ventricle hypertrophy, ventricle septal defect, and abnormal placement of the aorta. Unoxygenated blood from the right ventricle passes to the left ventricle and circulates to the body. The resulting cyanosis increases with age and activit

Tetralogy of Fallot

_____________is caused by a chromosomal disorder. Affected females have only one X chromosome, rather than the normal XX.

Turner's syndrome

_______________________is the most common solid tumor affecting children and infants. It may be present at birth, but symptoms do not usually appear until age 2 to 4. It is a highly malignant tumor of the kidney. Treatment may involve surgery and chemotherapy.

Wilms' tumor

Chromosomes are made of ultramicroscpoic units of ____________(DNA) arranged in a specific order. Each ultramicroscopic unit is called a gene.

deoxyribonucleic acid

congenital diaphragmatic hernia,

a congenital hole in the diaphragm;

imperforate anus

a failure of the anus to connect to the rectum.

anencephaly,

a severe congenital malformation resulting in the absence of the brain

__________________a rare genetic disorder characterized by abnormal development of the epiphyseal cartilage, resulting in decreased growth of long bone

achondroplasia,

genes aligned on a chromosome, a pair

alleles

Meckel's diverticulum,

an outpouching of the ileum

chromosomes determining body function

autosomes

obtaining squamous cells from the buccal cavity to evaluate sex chromosomes

buccal smear

There are two ways an individual acquires an abnormal gene: (1) or (2)

by mutation of the gene during meiosis, affecting the newly formed fetus, by passing the abnormal gene from the parents.

a congenital bilateral paralysis

cerebral palsy

affected child has a characteristic "scissors gait"

cerebral palsy

results from inadequate blood or oxygen supply during fetal development, birth, or infancy

cerebral palsy

the most common crippler of children

cerebral palsy

a narrowing of the descending or thoracic aorta

coarctation of aorta

birth defect

congenital abnormality

abnormality of the hip joint, or acetabulum

congenital hip dislocation

a hole in the diaphragm

diaphragmatic hernia

the gene in control

dominant

absence or closure of a normal opening of the esophagus

esophageal atresia

ultramicroscopic unit of deoxyribonucleic acid

gene

genetic pattern of the individual

genotype

sex cells

germ cells

The _____________ and its related great vessels are the most common sites of congenital defects

heart

an x-linked hereditary bleeding disorder passed from a carrier mother to a son

hemophilia

a matched pair of genes

homozygous

an abnormal accumulation of cerebrospinal fluid in the brain

hydrocephalus

treatment of choice is shunt placement

hydrocephalus

Genetic and developmental neurologic disorders are some of the most severe because of their long-term debilitating effects. Two of the most common disorders in this category are

hydrocephalus and cerebral palsy.

failure of the anus to connect to the rectum

imperforate anus

Chromosomes can be visualized by the process known as ______________. This involves taking a picture of a cell during mitosis, arranging the pairs in order from largest to smallest, and numbering them

karyotyping

visualizing and arranging chromosome pairs in order from largest to smallest

karyotyping

By the process of _________,germ cells reproduce cells that have onlyhalf, or 23 chromosomes

meiosis

reproduction of sex cells

meiosis

meningocele,

meningocele, where the meninges of the cord protrude through the opening, forming a fluid-filled sac on the skin

Cells reproduce through the process of_________where they duplicate, producing identical offspring

mitosis

reproduction of autosomes

mitosis

characterized by degeneration of the muscles

muscular dystrophy

commonly a sex-linked disorder passed from imperfecta mother to son

muscular dystrophy

life expectancy is late teens to early twenties

muscular dystrophy

most common type is Duchenne's

muscular dystrophy

affected children may be suspected victims of child abuse

osteogenesis

characterized by abnormally brittle bones

osteogenesis

significant sign is a blue coloration of the sclera

osteogenesis

oxygenated blood shunts abnormally from the aorta back to pulmonary artery

patent ducts arteriosus

expression of a trait such as brown hair

phenotype

Treatment for Cerebral Palsy Treatment involves

physical and speech therapy, orthopedic support, and, at times, surgery. Anticonvulsant medication may also be used.

the gene lacking control

recessive

a chronic hereditary form of anemia found predominately in black individuals

sickle cell anemia

body cells

somatic cells

an abnormal opening in the spinal column

spina bifida

most serious type is myelomeningocele

spina bifida

The three types OF SPINA BIFIDA include:

spina bifida occulta, meningocele, myelomeningocele,

Treatment for Hydrocephalus requires

surgically placing a shunt from the brain to the peritoneal cavity or right atrium of the heart to drain the excessive fluid.

Clubfoot, or_______________, is a congenital abnormality of the foot. The affected foot or feet turn inward, with the toes pointed down and the heel drawn up. Treatment may involve manipulation or application of a cast or splint

talipes equinovarus

frequently occurring deformity of the foot

talipes equinovarus

treatment may involve multiple casting

talipes equinovarus

a combination of four heart defects

tetralogy of Fallot

esophageal atresia

the absence or abnormal closure of part of the esophagus;

myelomeningocele

the most serious form where the meninges and a portion of the cord protrude through the opening

A _____________________, the most common heart defect, is a hole between the right and left ventricle that allows blood from the left ventricle to flow into the right ventricle. As with atrial septal defect, this oxygenated blood is recirculated to the lungs, causing an increased workload on the heart.

ventral septal defect

the most common heart defect

ventricular septal defect

spina bifida occulta,

which is asymptomatic and is the most common type;