Bella, where the hell have you been, loca? (imprinting disorders)
This term describes inheriting both copies of a chromosome from the same parent, a mechanism in several imprinting disorders.
What is uniparental disomy?
A 16-year-old boy presents with:
Aortic root dilation (Z ≥ 2)
Pectus excavatum
Arm span > height
Myopia
Under this clinical criteria, a diagnosis can be made with aortic root dilation + systemic score ≥ 7.
What is the Ghent criteria?
A patient with a family history of an autosomal dominant disorder says, “If I never get tested, then I don’t have to think about it.”
The patient represents this coping style.
What is avoidance?
Non-invasive prenatal testing is a common example of this testing in the prenatal genetic counseling setting.
What is a screening test?
This genetic disorder shows elevated C14 species as well as hypoketonic hypoglycemia on an acylcarntine analysis.
What is Very Long Chain Acyl-CoA Dehydrogenase Deficiency (VLCAD)?
A 9 year old girl presents with short stature. Physical exam shows macrocephaly, an inverted triangular face, protruding forehead, and low-set ears. Height is less than the 1st percentile. Methylation testing performed showed maternal UPD on chromosome 7. The child was diagnosed with this genetic condition.
What is Russel-Silver Syndrome?
A 38-year-old woman is diagnosed with colon cancer. Her father died of colon cancer at 45, and two of her paternal uncles were also diagnosed with colon cancer at 42 and 48. The affected relatives span two generations, and all are first- or second-degree relatives of each other.
This family meets this clinical criteria.
What is the Amsterdam II criteria?
When learning their child’s genetic diagnosis, a parent says, “This is my fault. I must have caused this somehow.”
The patient is displaying this emotional response.
What is guilt?
This diagnostic testing is the "gold standard" for diagnosing an individual with cystic fibrosis.
What is a sweat test?
Hereditary Fructose Intolerance has an elevation of these two metabolites.
A child presents with hypotonia, developmental delay, and hyperphagia. Standard chromosome microarray shows no deletion. Methylation-specific PCR reveals absence of the paternal methylation pattern in the PWS/AS region, while SNP array shows two maternal alleles and no paternal allele.
This molecular mechanism explains this finding.
What is uniparental disomy (UPD)?
A 27-year-old man presents with an osteosarcoma. His mother had breast cancer at 34.
This TP53-related clinical criteria applies to this individual.
What is the Chompret criteria?
A patient responds to complex medical information by saying, “I’m sure everything will be fine,” despite evidence to the contrary.
The patient is displaying this psychological defense mechanism.
What is denial?
A 3-year-old female presents with global developmental delay (GDD), intellectual disability (ID), and multiple minor dysmorphic features. Family history is non-contributory. According to the most recent ACMG and AAP guidelines, this test represents the most appropriate initial genetic testing strategy.
What is WES/WGS
A newborn screen (NBS) returns with an elevation in Tyrosine. To differentiate between Transient Tyrosinemia of the Newborn and Tyrosinemia Type 1, the lab performs a follow-up test for a specific metabolite. The presence of this metabolite is pathognomonic for Tyrosinemia Type 1.
What is succinylacetone?
A newborn male is admitted to the NICU for severe respiratory distress immediately after birth. Pregnancy was complicated by marked polyhydramnios. On exam, the infant has a small, bell-shaped thorax, abdominal wall laxity, a full, round face, short neck, and flat nasal bridge. Chest imaging demonstrates the classic “coat-hanger” appearance of the ribs. Further evaluation reveals paternal uniparental disomy of chromosome 14q32.2. The child was diagnosed with this genetic condition.
What is Kagami-Ogata syndrome?
A 10-year-old girl has four café-au-lait macules >5 mm and one axillary freckle on exam. No neurofibromas, Lisch nodules, or affected relatives. This girl does or does not meet clinical criteria for this genetic condition.
What is the girl does not meet clinical criteria for Neurofibromatosis 1?
A patient receiving unexpected results begins asking multiple detailed technical questions unrelated to the core issue, shifting away from emotional content.
The patient is using this defense mechanism.
What is intellectualization?
A 4-year-old boy presents with global developmental delay, large ears, and macroorchidism. The genetic counselor suspects Fragile X syndrome. This is the recommended ACMG laboratory method to determine if the boy has Fragile X syndrome.
What is PCR and southern blot methodology?
A 2-year-old child presents with loss of motor milestones and seizures. Family history is notable for an older sibling who died from a similar condition at age 3.
Laboratory studies are sent and show the following:
Hexosaminidase A enzyme activity: Normal
Hexosaminidase B enzyme activity: Normal
GM2 ganglioside: Elevated
A brain MRI is performed and shows widespread white matter changes and cortical atrophy. This child has been diagnosed with this condition.
What is Krabbe Disease?
A 1-month-old boy with hemihypertrophy & macroglossia presents for an evaluation. Genetic testing confirms the diagnosis of Beckwith-Wiedemann syndrome due to segmental mosaic paternal isodisomy. This patient's condition most likely arose through this mechanism.
What is Meiotic Nondisjunction?
A 16-year-old boy has an LDL cholesterol of 240 mg/dL. His father had a myocardial infarction at 38, and his paternal grandmother has known hyperlipidemia. He has tendon xanthomas on exam. This boy does or does not meet clinical criteria for this genetic condition.
What is the boy does meet clinical criteria for Familial Hypercholesterolemia.
A couple is conflicted about diagnostic testing. They list pros and cons and express uncertainty because their values differ.
The couple is showing this decision-making state.
What is ambivalence?
A 29-year-old G1P0 woman at 11 weeks gestation has a First Trimester Screen (FTS) showing an increased nuchal translucency (3.2 mm) and low PAPP-A. Her calculated risk for Trisomy 21 is 1 in 50. She is anxious and requests the "most accurate" next step to determine if the fetus has Down syndrome. This would be the most appropriate test.
What is a CVS?
These are the five C3 metabolites that are found to be elevated in Proponic Aciduria.
What is valine, odd chain fatty acids, methionine, isoleucine, therionine? (VOMIT)