Video Library
Short video lessons on rare diseases, lab techniques, quantitative genetics, principles, and counseling. Built for board prep and clinical reference.
27 videos so far.
Conditions(23)
Alternating hemiplegia of childhood (AHC)
Neurological Disorders
A 6-month-old infant presents with recurrent episodes of hemiplegia that alternate sides. Episodes are triggered by stress, bathing, or temperature changes and resolve with sleep. Over time, the child...
Andersen-Tawil syndrome (ATS/LQT7)
Cardiovascular Disorders
A 12-year-old girl presents with episodes of muscle weakness and cardiac palpitations. ECG shows a prolonged QT interval and prominent U waves. Physical exam reveals micrognathia, hypertelorism, low-s...
Angelman syndrome
Chromosome Abnormalities
A 2-year-old boy is evaluated for absent speech and severe developmental delay. He has frequent episodes of laughter, an ataxic gait with arm-flapping, and refractory seizures. EEG shows characteristi...
Beckwith-Wiedemann syndrome
Chromosome Abnormalities
A newborn presents with macrosomia, macroglossia, and an omphalocele. The baby has ear creases and indentations. The geneticist recommends tumor surveillance.
Blepharophimosis, ptosis, and epicanthus inversus syndrome (BPES)
Eye Disorders
A child presents with narrow horizontal palpebral fissures, drooping upper lids requiring chin elevation to see, and a skin fold ascending from the lower lid toward the nasal bridge. Eyelid surgery is...
Classic galactosemia
Metabolic Disorders
A newborn presents at 1 week of age with jaundice, hepatomegaly, and E. coli sepsis after starting breast milk or formula. Cataracts are noted on exam.
Cystic fibrosis
Respiratory Disorders
A newborn with meconium ileus is found to have an elevated immunoreactive trypsinogen on newborn screening. Sweat chloride is 85 mEq/L. Genetic testing reveals F508del homozygosity.
Glutaric aciduria type 1
Metabolic Disorders
A macrocephalic infant develops acute dystonia after a febrile illness. MRI shows frontotemporal atrophy and basal ganglia injury.
Glycogen storage disease type 2 (Pompe disease)
Metabolic Disorders
An infant with severe hypotonia has cardiomegaly with short PR interval. CK is elevated. Acid alpha-glucosidase activity is deficient.
Hereditary hearing loss (overview)
Hearing Disorders
A 2-day-old newborn fails the universal newborn hearing screen (OAE) bilaterally. Follow-up ABR confirms bilateral moderate-to-severe sensorineural hearing loss. Physical exam is unremarkable with no ...
Incontinentia pigmenti
Skin Disorders
A female infant develops vesicular lesions along the lines of Blaschko on her trunk and extremities in the first weeks of life. These evolve through verrucous and hyperpigmented stages. Her brother wa...
Isovaleric acidemia
Metabolic Disorders
A newborn with vomiting and metabolic acidosis has a distinctive "sweaty feet" odor. Isovalerylglycine is elevated in urine.
L1 syndrome (X-linked hydrocephalus)
Neurological Disorders
A male infant is born with severe hydrocephalus requiring shunting. He has adducted thumbs and later develops spastic paraplegia. Family history is notable for 2 affected maternal uncles with similar ...
Leber congenital amaurosis
Eye Disorders
A 6-month-old infant is noted to have roving eye movements (nystagmus), does not fix on objects, and has a normal fundus exam. Parents report he presses on his eyes frequently (oculodigital sign). An ...
Menkes disease
Neurological Disorders
A 3-month-old male infant presents with seizures, hypotonia, and failure to thrive. He has sparse, kinky, colorless hair ("steel wool"). Labs show low serum copper and ceruloplasmin.
Methylmalonic acidemia (MMA)
Metabolic Disorders
A newborn becomes lethargic with metabolic acidosis, hyperammonemia, and ketosis. Urine organic acids show markedly elevated methylmalonic acid.
Oculopharyngeal muscular dystrophy (OPMD)
Neurological Disorders
A 50-year-old French-Canadian man presents with progressive bilateral ptosis and difficulty swallowing. He tilts his head back to see and has lost weight due to dysphagia. His father had similar sympt...
Prader-Willi syndrome
Chromosome Abnormalities
A male infant is noted to have severe hypotonia at birth requiring nasogastric feeding. By age 4, his tone has improved and he now has an insatiable appetite, food-seeking behaviors, rapid weight gain...
Propionic acidemia
Metabolic Disorders
A newborn presents similarly to MMA with metabolic acidosis and hyperammonemia. Organic acids show elevated propionic acid and methylcitrate.
Russell-Silver syndrome
Chromosome Abnormalities
A 3-year-old is evaluated for severe growth restriction since birth. He has a triangular face with a prominent forehead, body asymmetry (one leg shorter than the other), and clinodactyly of the 5th fi...
Sotos syndrome (5q35 deletion)
Chromosome Abnormalities
A 2-year-old has macrocephaly, accelerated linear growth (above 97th percentile), and developmental delay with advanced bone age. Facial features include a prominent forehead, downslanting palpebral f...
Tyrosinemia type 1
Metabolic Disorders
An infant presents with liver failure, coagulopathy, and a cabbage-like odor. Succinylacetone is elevated in urine.
Wilson disease
Gastrointestinal Disorders
A 15-year-old presents with tremor and dysarthria. Slit-lamp exam reveals Kayser-Fleischer rings. Liver enzymes are mildly elevated. Ceruloplasmin is low and 24-hour urine copper is elevated.
Quantitative Genetics(2)
Bayesian Risk Assessment
Personalized Risk Assessment
Bayesian analysis updates a prior probability (based on pedigree or population data) with new conditional information (test results, family history, unaffected children) to calculate a posterior proba...
Relatedness, Consanguinity, and Coefficient of Inbreeding
Population Genetics
Consanguinity is the mating of individuals with a recent common ancestor. It increases the probability that offspring will be homozygous by descent for any allele present in that ancestor, raising the...
Genetics Principles(2)
Mitochondrial Genome
Molecular Genetics
The mitochondrial genome (mtDNA) is a 16.5 kb circular, double-stranded DNA molecule present in hundreds to thousands of copies per cell. It encodes 37 genes: 13 protein subunits of the oxidative phos...
Wilson's Rules & Teratogen Principles
Teratology
A teratogen is any agent (drug, infection, maternal metabolic disturbance, or physical exposure) that disrupts normal embryologic or fetal development. Wilson's rules, articulated in the 1960s and rev...