Genetic Disorder Flashcards
Both sexes are equally affected, both sexes transmit to offspring, no skipped generation, every child has a parent with disorder except new or spontaneous mutation
Autosomal dominant (AD)
Both sexes are equally affected, both sexes can transmit a copy of mutated gene, and their risk to have affected child is 25%, the disorder may be seen in one or more sibling, not all generations are affected
Autosomal recessive (AR)
No male-to-male transmission, only females transmit the disease to their sons, daughters are obligate carriers
X-linked recessive
Maternal transmission from egg to zygote; both males and females are affected
Mitochondrial inheritance
Hypotonia, upslanted palpebral fissures, epicanthal folds, systolic murmur, single transverse creases in hands, brachydactyly, broad space between the first and second toe
Down syndrome (trisomy 21)
Screening for hypothyroidism in cases of Down syndrome is at what age?
Newborn screening after birth, at 6 and 12months, then annually if normal
Acute myeloid leukemia (AML) is a higher risk in the patient with Down syndrome at what age?
Acute lymphocytic leukemia (ALL) is a higher risk in the patient with Down syndrome at what age?
> 1year
Newborn with Down syndrome with no murmur on physical examination
Echocardiography (50% of children with Down syndrome have a cardiac defect)
The most common cardiac defects associated with Down syndrome
AV canal defects, ventricular septal defect, atrial septal defect, and tetralogy of Fallot
The most common gastrointestinal defects associated with Down syndrome
Duodenal atresia, Hirschsprung disease
Newborn with clenched fist with overriding fingers, rocker bottom feet, small head, eyes, and mouth with low-set malformed ears, micrognathia, prenatal and postnatal growth deficiency, hypotonia, and ventricular septal defect
Trisomy 18 (Edward syndrome)
Newborn with cleft lip, cleft palate, microcephaly, microphthalmia, cutis aplasia, and postaxial polydactyly
Trisomy 13 (Patau syndrome)
A 5-year-old boy with intellectual disability, large hands and feet, long face with large ears, large testicles, and hyperextensible joints
Fragile X syndrome
Newborn girl with microcephaly, ocular hypertelorism, prominent glabella, frontal bossing (Greek helmet face), beaked nose, hypotonia, and seizures
Wolf–Hirschhorn syndrome (4p-deletion)
Newborn with a cat-like cry, hypotonia, microcephaly, moon face, widely-spaced eyes, down-slanting palpebral fissures, high-arched palate, and wide-flat nasal bridge
Cri du chat syndrome (5p-deletion)
Newborn with microcephaly, atresia of the ear canal, deep-set eyes, depressed mid-face, protruded mandible, legs are flexed, externally rotated, and in hyperabduction (frog-like position)
De Grouchy syndrome
Newborn with profound hypotonia, small for gestational age, feeding problems, failure to thrive, bitemporal narrowing, thin upper lip, almond- shaped eyes, hypogonadism, bilateral cryptorchidism, and small penis
Prader–Willi syndrome (PWS) (paternally derived deletion 15q11–13)
Child with hypotonia, jerky ataxic movement, fair hair, large chin and mandible, inappropriate bouts of laughter, and severe intellectual disability
Angelman syndrome (maternally derived deletion 15q11–13)
Child with an intellectual disability, supravalvar aortic stenosis, hypercalcemia, friendly “cocktail party” personality, and strabismus
Williams syndrome
The most common cause of hypercalcemia in a child with Williams syndrome
Idiopathic
Wilms tumor, Aniridia, Genitourinary malformation, Retardation (intellectual disability), long face, upward-slanting palpebral fissures, ptosis, and a beaked nose, due to the absence of PAX6 and WT1 (Wilms tumor) genes
WAGR syndrome
Newborn with Coloboma, Congenital Heart defects, choanal Atresia, growth and Retardation (intellectual disability), GU anomalies (hypogonadism), and Ear anomalies
CHARGE syndrome (gene defect CHD7 on chromosome 8q)
Vertebral defects, Anal atresia, Cardiac defects, Tracheoesophageal fistula, and/or Esophageal atresia, Renal anomalies, and Limb defects
VACTERL/VATER association
The most common association with VATER/ VACTERL syndrome
Congenital heart defects
Jaundice, bile duct paucity with cholestasis, peripheral pulmonary stenosis, butterfly vertebrae, triangular face with a pointed chin, long nose with broad mid-nose, and posterior embryotoxon
Alagille syndrome (20p12)