Artificial Intelligence (AI) Calculator for “Autosomal dominant/recessive inheritance calculator”
Understanding genetic inheritance patterns is crucial for predicting disease risks in families. Autosomal dominant and recessive inheritance calculators simplify this complex process.
This article explores the technical foundations, formulas, and practical applications of these calculators, enhancing genetic counseling accuracy.
- ¡Hola! ¿En qué cálculo, conversión o pregunta puedo ayudarte?
Example User Inputs for Autosomal Dominant/Recessive Inheritance Calculator
- Input 1: Parent 1 genotype: Aa (heterozygous dominant), Parent 2 genotype: aa (homozygous recessive)
- Input 2: Parent 1 genotype: AA (homozygous dominant), Parent 2 genotype: Aa (heterozygous dominant)
- Input 3: Parent 1 genotype: Aa, Parent 2 genotype: Aa (both heterozygous carriers)
- Input 4: Parent 1 genotype: aa, Parent 2 genotype: aa (both homozygous recessive)
Comprehensive Tables of Common Values in Autosomal Dominant/Recessive Inheritance Calculations
| Genotype Combination | Phenotype Probability (Dominant Trait) | Phenotype Probability (Recessive Trait) | Carrier Probability |
|---|---|---|---|
| AA x AA | 100% affected (dominant) | 0% | 0% |
| AA x Aa | 100% affected (dominant) | 0% | 0% |
| Aa x Aa | 75% affected (dominant) | 25% affected (recessive) | 50% carriers (recessive) |
| Aa x aa | 50% affected (dominant) | 0% | 50% carriers (recessive) |
| aa x aa | 0% | 100% affected (recessive) | 0% |
| Allele | Description | Symbol | Common Frequency in Population |
|---|---|---|---|
| Dominant allele | Allele causing trait expression when present | A | Varies by gene, often 0.01 – 0.1 |
| Recessive allele | Allele causing trait expression only when homozygous | a | Varies by gene, often 0.9 – 0.99 |
Fundamental Formulas for Autosomal Dominant/Recessive Inheritance Calculations
Calculating the probability of offspring inheriting specific genotypes or phenotypes requires understanding Mendelian genetics principles. Below are the essential formulas used in autosomal dominant and recessive inheritance calculators.
1. Genotype Probability Calculation
The probability of a child inheriting a particular genotype from two parents is calculated by combining the probabilities of each parent’s allele contribution.
- Example: For parents Aa (heterozygous) and aa (homozygous recessive), the probability child is Aa = 0.5 × 1 = 0.5 (50%).
2. Phenotype Probability for Autosomal Dominant Traits
Since dominant alleles mask recessive alleles, the phenotype probability is the sum of probabilities of genotypes containing at least one dominant allele.
- Where:
- Probability(AA) = Probability(child inherits dominant allele from both parents)
- Probability(Aa) = Probability(child inherits dominant allele from one parent and recessive from the other)
3. Phenotype Probability for Autosomal Recessive Traits
Recessive traits manifest only when the individual is homozygous recessive.
- Where: Probability(aa) = Probability(child inherits recessive allele from both parents)
4. Carrier Probability for Autosomal Recessive Traits
Carriers have one dominant and one recessive allele but do not express the recessive phenotype.
5. Hardy-Weinberg Equilibrium for Allele Frequency Estimation
In population genetics, allele frequencies can be estimated using the Hardy-Weinberg principle:
p² + 2pq + q² = 1
- Where:
- p = frequency of dominant allele (A)
- q = frequency of recessive allele (a)
- p² = frequency of homozygous dominant genotype (AA)
- 2pq = frequency of heterozygous genotype (Aa)
- q² = frequency of homozygous recessive genotype (aa)
Detailed Real-World Examples of Autosomal Dominant/Recessive Inheritance Calculations
Example 1: Autosomal Dominant Inheritance Calculation
Consider a couple where one parent is heterozygous for an autosomal dominant disorder (Aa), and the other parent is homozygous recessive (aa). Calculate the probability that their child will inherit the disorder.
- Parent 1 genotype: Aa (affected)
- Parent 2 genotype: aa (unaffected)
Step 1: Determine possible alleles from each parent.
- Parent 1 can pass either A (dominant) or a (recessive) allele, each with 50% probability.
- Parent 2 can only pass a recessive allele (a) with 100% probability.
Step 2: Calculate child genotype probabilities.
| Child Genotype | Probability | Phenotype |
|---|---|---|
| Aa | 0.5 × 1 = 0.5 (50%) | Affected (dominant trait) |
| aa | 0.5 × 1 = 0.5 (50%) | Unaffected |
Step 3: Calculate phenotype probability.
Interpretation: There is a 50% chance the child will inherit the autosomal dominant disorder.
Example 2: Autosomal Recessive Inheritance Calculation
Two parents are both heterozygous carriers (Aa) for an autosomal recessive disorder. Calculate the probability their child will be affected, a carrier, or unaffected.
- Parent 1 genotype: Aa (carrier)
- Parent 2 genotype: Aa (carrier)
Step 1: Determine possible alleles from each parent.
- Each parent can pass A or a allele with 50% probability.
Step 2: Calculate child genotype probabilities using a Punnett square:
| A (0.5) | a (0.5) | |
|---|---|---|
| A (0.5) | AA (0.25) | Aa (0.25) |
| a (0.5) | Aa (0.25) | aa (0.25) |
Step 3: Summarize genotype and phenotype probabilities.
| Genotype | Probability | Phenotype |
|---|---|---|
| AA | 25% | Unaffected, non-carrier |
| Aa | 50% | Carrier, unaffected |
| aa | 25% | Affected (recessive disorder) |
Interpretation: There is a 25% chance the child will be affected, 50% chance to be a carrier, and 25% chance to be unaffected and non-carrier.
Additional Technical Details and Considerations
- Penetrance and Expressivity: Autosomal dominant traits may exhibit incomplete penetrance or variable expressivity, affecting phenotype prediction accuracy.
- New Mutations: De novo mutations can introduce dominant alleles not inherited from parents, complicating calculations.
- Consanguinity: In recessive inheritance, consanguineous relationships increase the probability of homozygous recessive offspring.
- Population Allele Frequencies: Incorporating Hardy-Weinberg equilibrium and population data improves carrier risk estimation.
- Genetic Testing Integration: Combining calculator results with genetic testing data enhances clinical decision-making.
For authoritative guidelines on genetic inheritance and counseling, refer to the American College of Medical Genetics and Genomics (ACMG) and the NIH Genetics Home Reference.