List of genetic disorders facts for kids
A genetic disorder happens when there's a change or mistake in a person's genes or chromosomes. Think of your genes as a special instruction manual for your body. If there's a typo or a missing page in this manual, your body might not work exactly as it should. There are more than 6,000 known genetic disorders in humans. These conditions are not contagious; they are passed down from parents or happen when a new change occurs in the genes.
What Causes Genetic Disorders?
Genetic disorders are caused by different types of changes in our genetic material. Here are the main ways these changes can happen:
- Point Mutation (P): This is like a single letter typo in your gene's instruction manual. It's a small change in one specific spot within a gene.
- Deletion (D): This means a part of a gene or even a whole gene (or many genes) is missing. It's like a whole sentence or paragraph is gone from the instructions.
- Duplication (Dup): This is when a gene or a group of genes is copied too many times. It's like having a repeated sentence or paragraph in the instructions.
- Chromosome Abnormality (C): Our bodies have 23 pairs of chromosomes, which are like chapters in our instruction manual. A chromosome abnormality means there's an extra chromosome, a missing one, or a large part of a chromosome is rearranged.
- Trinucleotide Repeat Disorder (T): In these cases, a specific three-letter code in a gene is repeated many, many times. It's like a word being repeated over and over again in the instructions, making them too long.
Common Genetic Disorders
Many genetic disorders are known, and some are more common than others. Here are a few examples of genetic disorders and the type of genetic change that causes them:
| Disorder | Chromosome | Mutation Type |
|---|---|---|
| Angelman syndrome | 15q | Deletion, Chromosome Abnormality, Point Mutation |
| Canavan disease | 17p | Point Mutation |
| Charcot–Marie–Tooth disease | 17p12 | Duplication |
| Color blindness | X | Point Mutation |
| Cri du chat syndrome | 5 | Deletion |
| Cystic fibrosis | 7q | Point Mutation |
| DiGeorge syndrome | 22q | Deletion |
| Down syndrome | 21 | Chromosome Abnormality (extra chromosome 21) |
| Duchenne muscular dystrophy | Xp | Deletion |
| Familial hypercholesterolemia | 19 | Point Mutation |
| Hemophilia | X | Point Mutation |
| Klinefelter syndrome | X | Chromosome Abnormality (extra X chromosome) |
| Phenylketonuria | 12q | Point Mutation |
| Sickle cell disease | 11p | Point Mutation |
| Tay–Sachs disease | 15q | Point Mutation |
| Turner syndrome | X | Chromosome Abnormality (missing or changed X chromosome) |
More Genetic Disorders
There are many different types of genetic disorders, each with its own unique cause and effects on the body. Some are caused by changes in a single gene, while others involve larger changes to chromosomes. Scientists are always learning more about these conditions and how to help people who have them.
Here is a list of some other genetic disorders:
| Disorder | Chromosome or Gene | Type | Prevalence (how common it is) |
|---|---|---|---|
| Achondroplasia | FGFR3 (4p16.3) | dominant | 1 in 27,500 |
| Adrenoleukodystrophy | ABCD1 (X) | recessive | 1 in 17,000 |
| Albinism | 1 in 18,000-20,000 | ||
| Alzheimer's disease | PSEN1, PSEN2, APP, APOEε4 | 1 in 177 (for all types, including genetic) | |
| Angelman syndrome | UBE3A | 1 in 12,000-20,000 | |
| Ataxia telangiectasia | ATM | 1 in 40,000-1,000,000 | |
| Beckwith–Wiedemann syndrome | IGF-2, CDKN1C, H19, KCNQ1OT1 | 1 in 15,000 | |
| Bloom syndrome | 15q26.1 | 1 in 480,000 | |
| Canavan disease | ASPA | 1 in 6,400-13,500 | |
| Charcot–Marie–Tooth disease | PMP22, MFN2 | 1 in 2,500 | |
| Cystic fibrosis | CFTR (7q31.2) | Deletion or Substitution | 1 in 100,000 |
| Down syndrome | 21 | Chromosome Abnormality (trisomy) | 1 in 1,000-1,100 |
| Duchenne muscular dystrophy | Dystrophin | X-linked recessive | |
| Ehlers–Danlos syndrome | Multiple genes | dominant | 1 in 5,000 |
| Epidermolysis bullosa | Multiple genes | dominant or recessive | 11.08 in 1,000,000 |
| Fragile X syndrome | FMR1 | Trinucleotide Repeat | 1 in 4,000 males, 1 in 8,000 females |
| Friedreich's ataxia | FXN | Trinucleotide Repeat | 1 in 50,000 (U.S.) |
| Gaucher disease | GBA (1) | 1 in 20,000 | |
| Hemophilia | FVIII | 1 in 7,500 males (hemophilia A) | |
| Huntington's disease | chromosome 4 HTT gene | autosomal dominant | 1 in 10,000 in US |
| Marfan syndrome | 15q | dominant | 1 in 5,000-10,000 |
| Muscular dystrophy | multiple | Autosomal Recessive, Autosomal Dominant, X-linked | |
| Myotonic dystrophy | DMPK, CNBP | dominant or Trinucleotide Repeat | 1 in 8,000 |
| Neurofibromatosis type I | 17q11.2 | ||
| Niemann–Pick disease | SMPD1, NPA, NPB, NPC1, NPC2 | 1 in 250,000 (types A and B) | |
| Noonan syndrome | Multiple genes | dominant | 1 in 1,000 |
| Osteogenesis imperfecta | COL1A1, COL1A2, IFITM5 | dominant | 1 in 15,000-20,000 |
| Phenylketonuria | PAH | recessive | 1 in 12,000 |
| Polycystic kidney disease | PKD1 (16) or PKD2 (4) | Point Mutation | |
| Prader–Willi syndrome | 15 | paternal imprinting | 1 in 10,000-30,000 |
| Rett syndrome | MECP2 | dominant, often new change | 1 in 8,500 females |
| Sickle cell anemia | 11p15 | Point Mutation | |
| Spinal muscular atrophy | 5q | 1 in 10,000 | |
| Tay–Sachs disease | HEXA (15) | recessive | |
| Turner syndrome | X | Chromosome Abnormality (monosomy) | 1 in 2,000-2,500 live female births |
| Williams syndrome | 7q11.23 | dominant | 1 in 10,000 |
| Wilson disease | ATP7B | recessive | 1 in 30,000 |
