[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Medical genetics](https://durgical.com/en/genetics/) › The molecular basis of disease

# The molecular basis of disease

From the altered gene to the protein and the clinical picture, in the model disorders.

13 pages

## Topics

- [**Hemoglobin variants (HbA, HbA2, HbF, HbS, HbC)** Hemoglobin changes chains from fetus to adult, and a single amino-acid change is enough to cause…](https://durgical.com/en/biochemistry/topics/hemoglobin-variants/)

## Conditions and syndromes

- [**Sickle cell disease** An inherited hemoglobin disease in which red cells bend into a sickle shape, block vessels and…](https://durgical.com/en/conditions/sickle-cell-disease/)
- [**Thalassemias (α and β)** Inherited diseases in which too little α or β globin is made; red cells come out small and few…](https://durgical.com/en/conditions/thalassemias/)
- [**Phenylketonuria (PKU)** In phenylketonuria the body cannot process the phenylalanine in protein; untreated from birth…](https://durgical.com/en/conditions/phenylketonuria/)
- [**I-cell disease (mucolipidosis II)** In I-cell disease lysosomal enzymes miss their shipping tag and leave the cell; coarse features…](https://durgical.com/en/conditions/i-cell-disease/)
- [**Familial hypercholesterolemia** An inherited disorder in which the liver cannot clear LDL cholesterol from the blood; it causes…](https://durgical.com/en/conditions/familial-hypercholesterolemia/)
- [**Cystic fibrosis** An inherited disease that makes mucus thick and sticky, damaging the lungs, pancreas and other…](https://durgical.com/en/conditions/cystic-fibrosis/)
- [**Duchenne muscular dystrophy** An inherited disease of boys in which dystrophin is missing: muscles are damaged and weaken from…](https://durgical.com/en/conditions/duchenne-muscular-dystrophy/)
- [**Spinal muscular atrophy** Spinal muscular atrophy is an inherited disease in which the nerve cells that move muscles die…](https://durgical.com/en/conditions/spinal-muscular-atrophy/)
- [**Huntington disease** An inherited brain disease causing involuntary movements, mood changes and dementia, due to a…](https://durgical.com/en/conditions/huntington-disease/)
- [**Fragile X syndrome** The most common inherited cause of intellectual disability and of genetic autism; a CGG repeat…](https://durgical.com/en/conditions/fragile-x-syndrome/)
- [**MELAS (mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes)** MELAS is a maternally inherited mitochondrial disease that causes stroke-like episodes, lactic…](https://durgical.com/en/conditions/melas/)
- [**MERRF (myoclonic epilepsy with ragged-red fibres)** A maternally inherited mitochondrial disease of myoclonic jerks, seizures, unsteadiness and…](https://durgical.com/en/conditions/merrf/)

[← Medical genetics](https://durgical.com/en/genetics/)

This section is an index: it gathers pages from Biochemistry, Pathology, Embryology and other sections without repeating them. Educational content; it does not replace a geneticist's assessment or genetic counselling.

Representative model, for educational purposes only.

---
Source: https://durgical.com/en/genetics/molecular-basis/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/genetics/molecular-basis/