Mosaicism
I have café-au-lait macules and neurofibromas limited to one side of my body because my pathogenic variant occurred after fertilization
What is mosaic/ segmental NF1?
This maternally inherited disorder presents with painless, subacute bilateral vision loss in young adults
What is Leber Hereditary Optic Neuropathy (LHON)?
This baby wearing a “I Love Vermont” onesie presents with sweet smelling urine
What is Maple syrup urine disease ?
I Love Vermont: (I= isoleucine, L= leucine, V= valine)
6 café-au-lait macules and Lisch nodules
What is NF1?
APC
What is colonoscopies in adolescence?
This disorder is caused by a postzygotic pathogenic variant in GNAS and presents with café-au-lait macules, fibrous dysplasia, and precocious puberty
What is McCune-Albright Syndrome?
This disorder presents with stroke-like episodes before age 40, seizures, hearing loss, diabetes, and lactic acidosis
What is MELAS ?
An infant presents with developmental delay, hepatosplenomegaly, a cherry-red macula, and no hepatocellular dysfunction. Enzyme testing reveals deficient β-hexosaminidase A activity
What is Tay-Sachs Disease?
Three facial angiofibromas and a shagreen patch
What is Tuberous Sclerosis Complex?
RB1
What is retinoblastoma from infancy?
A parent tests negative for their child’s pathogenic variant on blood testing but has multiple affected children because the mutation is confined to the germ cells due to this
What is Gonadal/ Germline Mosaicism?
This syndrome presents with progressive external ophthalmoplegia, pigmentary retinopathy, heart block, and onset before age 20
What is Kearns-Sayre syndrome?
A neonate develops lethargy, poor feeding, respiratory alkalosis, hyperammonemia, and low citrulline without metabolic acidosis
What is OTC deficiency ?
Multiple mucocutaneous pigmentation and at least two PJ polyps
What is Peutz-Jeghers Syndrome?
PTEN
What is ultrasounds starting at 7 years old?
Following CVS, chromosome analysis demonstrates mosaic trisomy 16. The fetus appears normal on ultrasound. What phenomenon must be considered before counseling the patient?
What is confined Placental mosaicism?
This syndrome presents with myoclonic epilepsy, ragged-red fibers on muscle biopsy, ataxia, and sensorineural hearing loss
What is MERRF syndrome?
A child has angiokeratomas, acroparesthesias, hypohidrosis, progressive kidney disease, and hypertrophic cardiomyopathy. The disorder is X-linked
What is Fabry Disease?
Three major diagnostic criteria including ectopia lentis and aortic root dilation
What is Marfan syndrome?
TP53
What is whole body imaging from birth?
Females with this x-linked condition affecting the muscles are considered manifesting carriers due to somatic mosaicism
What is Duchenne Muscular Dystrophy?
Two siblings have the same mitochondrial disorder, but only one has severe symptoms despite inheriting the same pathogenic mitochondrial DNA variant from their mother. What genetic principle best explains this difference?
What is Heteroplasmy?
This fatty acid oxidation disorder presents with hypoketotic hypoglycemia, elevated C8 acylcarnitine, and sudden decompensation after prolonged fasting
What is Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency?
Hypertelorism, a bifid uvula (or cleft palate), and widespread arterial aneurysms and tortuosity in an individual
What is Loey-Dietz Syndrome?
What syndrome requires surveillance for CNS hemangioblastomas, renal cell carcinoma, pheochromocytoma, retinal angiomas, and pancreatic lesions beginning in childhood
What is Von Hippel Lindau?