Chapter 5: Genetic and Developmental Disorders · Pathology

Study path

Follow the order or jump to the concept you need. Every topic has a Deep Learning and a High-Yield view of the same facts, and ends with a short knowledge check.

0 of 6 topics studied0 of 60 questions correct

5.134 minUp nextMutations and Mendelian inheritanceA mutation is a permanent change in DNA. Whether it reaches the next generation, what it does to the protein, and how it travels through a family decide who is affected and what the risk is for the next child.Germline and somatic mutationsWhat a mutation does to the messageTrinucleotide repeats and anticipationReading a pedigree: four Mendelian patterns+4
5.238 minChromosomal disorders and syndromesWhole chromosomes or large pieces are gained, lost or moved. The phenotype follows the dose of genes; the recurrence risk follows whether the error was a one-off in one gamete or is carried, balanced, by a parent.Nondisjunction and mosaicismDeletions and translocationsX inactivation and Barr bodiesDown syndrome (trisomy 21)+3
5.330 minBeyond Mendel: repeats, mitochondria, imprinting and multifactorial traitsSome disorders break the Mendelian ratios: a repeat that grows as it passes through mothers, DNA that only mothers transmit, genes that work only from one parent's copy, and traits built from many genes plus environment.Three questions about any chromosome problemFragile X syndromeMitochondrial inheritanceGenomic imprinting: Prader–Willi and Angelman+1
5.430 minSex development, congenital anomalies and maternal factorsSexual development is a cascade in four layers, chromosomes → gonads → internal ducts → external genitalia, and a block at one layer leaves the layers above it intact. Congenital anomalies are named by how they arose, and several maternal conditions act on the fetus directly.Four layers of sex developmentOvotesticular DSD (true hermaphroditism)Androgen insensitivity and 5α-reductase deficiencyCongenital adrenal hyperplasia (21-hydroxylase)+2
5.530 minCongenital infections and teratogensA teratogen is anything that crosses into the embryo or fetus and disturbs development. What it does depends on the agent and, as much, on when it arrives.Congenital infections (TORCH and others)Drugs and exposures: the lecture's teratogen tableFetal alcohol syndromeCritical periods: when an exposure arrives
5.632 minPerinatal disease, prenatal testing and agingAround birth, immaturity is the main enemy: surfactant, gut and brain vessels are not ready. Prenatal testing separates a risk estimate (screening) from an answer (diagnosis). At the other end of life, accumulated damage and failing repair drive aging.Pregnancy loss, prematurity and growthNeonatal respiratory distress syndromeNEC, intraventricular hemorrhage and SIDSScreening: ultrasound, serum markers and AFP+2

Practice

Interactive labPedigree Lab, The Missing Arrow, Almost Twins and One Fact Changes. Each also appears inside the topic where it helps most.High-yield cards40 cards on clues, comparisons and mechanisms worth recalling.Chapter reviewBringing it together: will it happen again?, then 16 mixed case-based questions with explanations.Case and source mapWhat each supplied case and lecture question tests (43 items), linked to where it is practised, with the source page map.

How the ideas connect

13 bridges carry one concept into the next, within this chapter and across chapters. Each is taught where you first need it.