Dannah Louise Palanca

Trisom Disorder 3. Down Syndrome (Trisomy 21)

1. Trisomy 13 Syndrome (Patau ● Chromosomal Basis: An extra chromosome 21 is
Syndrome) present (karyotype: 47XY+21 or 47XX+21).
○ Variants: May also occur via translocation
● Chromosomal Basis: The affected child has an or mosaicism.
extra chromosome 13 (karyotype: 47XY+13 or ● Incidence: Common — about 1 in 800 births; risk
47XX+13). increases with maternal age >35 and paternal
● Incidence: Rare — approximately 0.45 per 1,000 age >55 .
live births. ● Physical Features:
● Cognitive Impairment: Profound cognitive ○ Broad, flat nose and epicanthal folds at
impairment is common. the eyes.
● Physical Features & Anomalies: ○ Upward slanting palpebral fissures.
○ Midline defects such as cleft lip and ○ Brushfield spots (white specks on the
palate. iris).
○ Congenital heart defects, especially ○ Protruding tongue due to small oral
ventricular septal defects. cavity.
○ Abnormal genitalia. ○ Flat occiput, short neck, and loose neck
○ Microcephaly with forebrain and forehead skin.
abnormalities. ○ Low-set ears.
○ Eye abnormalities like microphthalmos ○ Hypotonia (poor muscle tone).
(small eyes) or anophthalmia (absent ○ Short, thick fingers, especially curved
eyes). little fingers.
○ Low-set ears. ○ Wide space between first and second
○ Polydactyly (extra fingers) and toes.
rocker-bottom feet are common. ○ Simian crease (single horizontal crease
● Prognosis: Most children do not survive beyond across the palm) .
early childhood . ● Cognitive Effects: Usually mild to moderate
intellectual disability (IQ 50–70); some cases may
be more severe.
2. Trisomy 18 Syndrome (Edwards
● Associated Health Issues:
Syndrome) ○ Congenital heart disease, especially
atrioventricular septal defects.
● Chromosomal Basis: Presence of an extra ○ Duodenal atresia or stenosis.
chromosome 18 (karyotype: 47XY+18 or ○ Frequent respiratory infections due to
47XX+18). immune dysfunction.
● Incidence: Approximately 0.23 per 1,000 live ○ Increased risk of leukemia, particularly
births. acute lymphoblastic leukemia.
● Cognitive Impairment: Severe intellectual ○ Visual disorders like strabismus or
disability. cataracts.
● Growth and Development: ● Lifespan: Although some can live into their
○ Babies are usually small for gestational 50s–60s, aging is accelerated .
age. ● Detection & Support:
○ Markedly low-set ears and a small jaw ○ Diagnosable in utero via ultrasound and
(micrognathia). genetic testing (amniocentesis/CVS).
○ Congenital heart defects. ○ Early educational intervention and health
○ Misshapen digits, particularly a precautions are crucial .
characteristic index finger overriding
others.
○ Rocker-bottom feet (rounded soles).
● Prognosis: Most children die in infancy due to
severe organ defects .
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○ Lack of development of secondary sex
characteristics at puberty (e.g., sparse

S Chrom om Abnormalitie ●
facial/body hair).
Cognitive and Psychosocial Aspects:
○ May have mild cognitive impairments or
1. Turner Syndrome (45,X or 45,X0) learning difficulties, especially
language-based.
● Karyotype: 45,X — only one functional X ● Diagnosis:
chromosome; no second sex chromosome. ○ Often not detected until puberty or when
● Phenotypic Sex: Female. infertility is investigated.
● Incidence: ~1 in 10,000 live births. ○ Confirmed through karyotyping .
● Primary Features:
○ Short stature. 3. Triple X Syndrome (47,XXX)
○ Webbed neck and low posterior hairline.
○ Lack of secondary sex characteristics ● Karyotype: 47,XXX — female with an extra X
(except pubic hair). chromosome.
○ Streak ovaries (small, nonfunctional); ● Phenotypic Sex: Female.
results in infertility. ● Incidence: About 1 in 1,000 female births.
○ Edema of hands and feet at birth. ● Clinical Manifestations:
○ Congenital anomalies, especially ○ Often asymptomatic.
coarctation of the aorta and renal ○ Normal sexual development and fertility.
abnormalities. ○ Some may experience taller stature,
● Cognitive and Psychosocial Aspects: learning disabilities, or delayed
○ Intelligence is usually normal. language/motor development.
○ Some may have learning disabilities. ● Diagnosis: Often found incidentally through
○ Socioemotional adjustment issues may genetic testing; not prominently discussed in this
arise due to infertility or appearance. edition of the text, indicating minimal clinical
● Diagnosis: symptoms in many cases.
○ Detected prenatally via ultrasound

●
(notable neck folds).
Treatment: Singl -Gen Disorder /
Inherite Metaboli Disorder
○ Human growth hormone can enhance
height.
○ Estrogen therapy (typically begun at ~13
years) promotes secondary sexual
1. Tay-Sachs Disease
characteristics and helps prevent
osteoporosis.
● Inheritance: Autosomal recessive.
○ Induced menstruation via cyclic estrogen
● Deficiency: Hexosaminidase A enzyme (involved
therapy, though it does not restore
in lipid metabolism).
fertility.
● Pathophysiology: Lipids accumulate in nerve
cells due to enzyme deficiency, leading to
2. Klinefelter Syndrome (47,XXY) cognitive deterioration and blindness.
● Population Risk: Predominantly seen in
● Karyotype: 47,XXY — male with an extra X Ashkenazi Jews.
chromosome. ● Clinical Signs:
● Phenotypic Sex: Male. ○ Normal appearance at birth.
● Incidence: ~1 in 1,000 live births. ○ Exaggerated Moro reflex and mild
● Primary Features: hypotonia in early infancy.
○ Small testes with ineffective sperm ○ Cherry-red macula on ophthalmic exam
production (infertility). (due to lipid deposits).
○ Gynecomastia (breast development), ○ Progressive motor deterioration,
increased risk of male breast cancer. spasticity, seizures, and blindness by age
2.
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● Prognosis: Death usually occurs between ages 4. Phenylketonuria (PKU)
3–5 from malnutrition and pneumonia.
● Diagnosis: Prenatal detection via amniocentesis; ● Inheritance: Autosomal recessive.
carrier status via enzyme assay . ● Enzyme Deficiency: Phenylalanine hydroxylase.
● Pathophysiology: Inability to convert
2. Cystic Fibrosis phenylalanine to tyrosine, leading to toxic
buildup.
● Inheritance: Autosomal recessive. ● Clinical Manifestations:
● Cause: Mutation in gene on chromosome 7, ○ Severe intellectual disability if untreated.
affecting chloride transport and leading to thick ○ Fair complexion, eczema, seizures, and
mucus secretions. “mousy” urine odor
● Systems Affected: Primarily lungs, pancreas, and ● Diagnosis: Universal newborn screening via
intestines. heel-prick after at least two days of feeding.
● Clinical Manifestations: ● Management:
○ Chronic respiratory infections, meconium ○ Strict low-phenylalanine diet using
ileus in newborns. synthetic formulas (e.g., Lofenalac).
○ Poor nutrient absorption due to ○ Monitor phenylalanine and hemoglobin
pancreatic enzyme blockage. levels.
○ Infertility (especially in males due to thick ○ Indefinite dietary restriction is
semen; cervical mucus may block sperm recommended, including preconception
in females). and pregnancy in affected women to
● Diagnosis: Newborn screening and genetic prevent fetal damage .
testing.
● Treatment: 5. Sickle Cell Anemia
○ Pancrelipase (Pancrease) enzyme
supplementation. ● Inheritance: Autosomal recessive.
○ Bronchodilators, antibiotics, chest ● Cause: Mutation in beta-globin gene — valine
physiotherapy. replaces glutamic acid.
○ Iron supplementation and diabetes ● Result: Hemoglobin S causes sickling of red
screening during pregnancy. blood cells under stress (e.g., low oxygen,
● Pregnancy Considerations: Risk for preterm labor dehydration).
and perinatal death if maternal oxygenation is ● Clinical Signs:
compromised. ○ Symptoms typically appear after 6
months of age.
3. Maple Syrup Urine Disease (MSUD) ○ Vaso-occlusive crises with severe pain,
anemia, jaundice, and organ ischemia.
● Inheritance: Autosomal recessive. ○ Risk of stroke, acute chest syndrome,
● Defect: Inability to metabolize branched-chain and splenic sequestration.
amino acids (leucine, isoleucine, valine). ● Diagnosis: Newborn screening or prenatal via
● Signs: Normal at birth; then: chorionic villi sampling.
○ Feeding difficulty, loss of Moro reflex, ● Genetics: Both parents must be carriers; 1 in 400
irregular respirations. African American infants are affected; 1 in 12
○ Progresses to seizures, opisthotonos, have the trait.
and coma if untreated. ● Management: Hydration, oxygenation, pain
○ Urine smells like maple syrup due to management, and infection prevention .
ketoacids.
● Diagnosis: Newborn screening.
● Management:
○ Diet low in the offending amino acids,
high in thiamine.
○ Requires intensive dietary counseling.
○ Dialysis may be used acutely to reduce
serum amino acid levels .
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Neurologica an Developmenta
● Incidence: 3–7% of school-age children; more
common in boys.
● Etiology: Likely genetic; also linked to lead
Syndrome exposure, prenatal drug exposure, or neglect.
● Behavioral Signs:
○ Poor focus, easily distracted, acts without
1. Fragile X Syndrome thinking.
○ Excessive movement: fidgeting, climbing,
● Genetic Basis: X-linked disorder with a defect on
running.
the long arm of the X chromosome.
● Learning Challenges:
● Incidence: ~1 in 1000 live births.
○ Problems with sequencing, arithmetic,
● Main Features:
spelling, reading.
○ Most common inherited cause of
○ May appear unintelligent but usually
cognitive impairment in males.
have normal IQ.
○ Inadequate synaptic protein response
● Management:
causes cognitive and behavioral
○ Behavioral therapy, environmental
symptoms.
structuring.
● Physical Characteristics:
○ Medications (e.g., methylphenidate) to
○ Large head, long face, high forehead,
improve attention span.
prominent jaw, large protruding ears.
○ Parents should be taught to provide
○ Hyperextensible joints and possible
structure, fairness, and positive
cardiac anomalies.
reinforcement .
● Behavioral Signs:
○ Maladaptive behaviors before puberty:
hyperactivity, autistic traits. 5. Huntington Chorea (Huntington
○ Speech and arithmetic deficits are Disease)
marked .
● Inheritance: Autosomal dominant disorder.
2. Angelman Syndrome ● Genetic Basis: Mutation on chromosome 4.
● Manifestation Age: Symptoms usually begin at
Not specifically mentioned in the book. Typically, this 35–45 years.
syndrome involves: ● Symptoms:
○ Progressive neurological decline,
● Deletion or mutation on maternal chromosome including motor loss and intellectual
15. deterioration.
● Characterized by severe developmental delays, ● Prognosis: No cure; leads to fatal deterioration.
happy demeanor, jerky movements, lack of ● Testing: Genetic analysis is available to detect
speech, and seizures. carriers before symptoms begin .

3. KAT6A Syndrome 6. Schizophrenia

Not included in this edition. It is a rare genetic disorder Not detailed in this text. Schizophrenia is a chronic
involving mutations in the KAT6A gene, usually resulting mental disorder characterized by:
in:
● Delusions, hallucinations, disorganized speech,
● Developmental delay, hypotonia, feeding social withdrawal, and cognitive dysfunction.
difficulties, speech delay, and sometimes cardiac ● Typically emerges in late adolescence or early
or facial anomalies. adulthood.

4. ADHD (Attention-Deficit/Hyperactivity
Disorder)

● Definition: Persistent pattern of inattention,

hyperactivity, and impulsiveness before age 7.
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Craniofacia an Skeleta
● Management:
○ Cleft lip repair typically done between
2–10 weeks of age.
Syndrome ○ Cleft palate repair may follow a two-stage
approach: soft palate (3–6 months), hard
palate (15–18 months).
1. Wolf-Hirschhorn Syndrome ○ Speech therapy, hearing screening, and
orthodontic follow-up are essential .
Not described in the book. For context: It is caused by a
● Nursing Care:
deletion on the short arm of chromosome 4 (4p-) and is
○ Prevent aspiration.
associated with:
○ Provide nutritional support and parental
emotional support.
● Distinct craniofacial appearance (Greek warrior
○ Emphasize bonding and early surgical
helmet profile)
correction for optimal outcomes .
● Severe growth retardation, intellectual disability
● Seizures, heart defects
4. Crouzon Syndrome
2. Cri-du-chat Syndrome (46XX5p⁻ or Not included in this edition of the book. For context: It is a
46XY5p⁻) craniosynostosis syndrome caused by mutations in the
FGFR2 gene, characterized by:
● Genetic Cause: Partial deletion of the short arm
of chromosome 5. ● Premature fusion of cranial suture
● Key Feature: Characteristic cat-like cry in infancy, ● Bulging eyes, underdeveloped upper jaw
caused by abnormal larynx and nervous system ● Normal intelligence, though complications like
development. hydrocephalus or airway obstruction may arise
● Other Physical Traits:
○ Microcephaly (small head) 5. Carpenter Syndrome
○ Hypertelorism (wide-set eyes)
○ Downward slant to palpebral fissures Not covered in the text. In general clinical genetics:
● Cognitive Impact: Severe cognitive impairment is
typical. ● A rare autosomal recessive condition
● Diagnosis: Based on clinical signs and confirmed ● Features include craniosynostosis, polydactyly,
with chromosomal analysis . obesity, and intellectual disability
● Caused by mutations in the RAB23 gene
3. Cleft Lip and Palate

● Etiology: Muscul keleta an Connectiv

○ Polygenic inheritance or teratogenic
exposure during weeks 5–8 of gestation. ssu Disorder
○ Sometimes part of syndromes like Pierre
Robin or others. 1. Duchenne Muscular Dystrophy (DMD)
● Incidence:
○ Cleft lip: ~1 in 750 births (more common ● Inheritance: X-linked recessive (affects boys).
in boys) ● Onset: Symptoms typically appear around age 3.
○ Cleft palate alone: ~1 in 2000 births ● Early Signs:
(more common in girls) ○ Delayed motor milestones (walking,
○ Combined cleft lip and palate in ~46% of standing).
cases ○ Waddling gait, toe walking, difficulty
● Presentation: climbing stairs.
○ Varies from minor notching of the lip to ○ Gower’s Sign: Child uses hands to push
full separation into the nasal cavity. off legs to stand (classic feature).
○ Feeding difficulties are common; use of ● Progression:
special feeders like Haberman feeders is ○ Calf hypertrophy (muscle tissue replaced
often required . by fat/connective tissue).
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○ Loss of ambulation by adolescence. 5. Dyskeratosis Congenita
○ Scoliosis, cardiomyopathy, respiratory
failure in late stages. Not included in the book. Clinical note (external
● Diagnosis: reference):
○ Muscle biopsy, elevated serum creatine
kinase, EMG studies. ● Rare genetic disorder involving defective
● Management: telomere maintenance.
○ Physical therapy, splinting, bracing, ● Features: Nail dystrophy, oral leukoplakia,
respiratory support, and possibly abnormal skin pigmentation.
wheelchair use by middle school. ● Associated with bone marrow failure and
○ Death commonly occurs by age 20 due increased cancer risk.
to pulmonary dysfunction .

2. Marfan Syndrome
Other Geneti Condition
Not covered in this edition of the text. Clinical note 1. Progeria
(external reference):
Not discussed in the textbook. Clinical context (external
reference):
● Autosomal dominant connective tissue disorder
involving FBN1 gene.
● Also known as Hutchinson-Gilford Progeria
● Features: Tall stature, long limbs, aortic
Syndrome, a rare genetic disorder causing
aneurysms, lens dislocation, scoliosis, and mitral
premature aging.
valve prolapse
● Caused by mutation in the LMNA gene.
● Affected children typically die of cardiovascular
Immunologica an Hematologi complications in their teens.

Disorder 2. DiGeorge Syndrome

● Also known as: 22q11.2 deletion syndrome.
3. Duncan Disease (X-linked Lymphoproliferative ● Cause: Chromosome 22q11.2 deletion leads to
Syndrome) underdevelopment of the thymus and parathyroid
glands.
Not included in the book. Clinical note (external ● Immunologic effect: Results in T-lymphocyte
reference): deficiency, impairing cell-mediated immunity.
● Associated anomalies:
○ Cardiac defects
● X-linked recessive, affecting response to ○ Hypocalcemia
Epstein-Barr virus. ○ Cleft palate
● Causes uncontrolled lymphocyte proliferation, ○ Facial anomalies
liver dysfunction, hypogammaglobulinemia, and ● Children are prone to viral and fungal infections
lymphoma. due to impaired T-cell function .

4. Alport’s Syndrome 3. Williams Syndrome

Not mentioned in this edition. Clinical note (external Not described in the book. Clinical context (external
reference): reference):

● Genetic disorder affecting basement membranes, ● Microdeletion on chromosome 7q11.23, including

especially in kidneys. the ELN gene.
● Symptoms: Progressive glomerulonephritis, ● Features include:
sensorineural hearing loss, and ocular ○ Elfin facial features
abnormalities. ○ Mild to moderate intellectual disability
● Diagnosis: Genetic testing, kidney biopsy. ○ Overfriendly personality
○ Supravalvular aortic stenosis
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4. Albinism

Not specifically detailed in the book. Clinical context

(external reference):

● Group of inherited disorders causing

hypopigmentation of skin, hair, and eyes.
● Due to defects in melanin production (commonly
tyrosinase gene).
● May result in vision problems like nystagmus,
photophobia, and reduced visual acuity.

5. Color Blindness

● Definition: Inability to perceive color correctly.

● Inheritance: Sex-linked trait; affects ~8% of boys.
● Cause: Absence of specific cones in the retina
(for red, green, or blue).
● Associated conditions: Higher incidence in
children with hemophilia, nystagmus, or G6PD
deficiency.
● Detection: Color plate tests in preschool-age
children.
● Management: No treatment available; focus on
early detection to prevent learning difficulties and
ensure safety awareness (e.g., traffic lights) .

6. Spina Bifida

Not directly detailed under this term in the book, but

generally covered as a neural tube defect (NTD). Clinical
context (external reference):

● Failure of neural tube closure during

embryogenesis.
● Types:
○ Spina bifida occulta (hidden, mild form)
○ Meningocele (meninges protrude)
○ Myelomeningocele (spinal cord and
meninges protrude—most severe)
● Often associated with hydrocephalus and
Arnold-Chiari malformation.
● Prevention: Adequate folic acid intake before
conception and during early pregnancy.