What is the risk of passing on genetic disorders, such as Autism Spectrum Disorder (ASD), to our offspring if we have no family history of genetic disorders and are trying to conceive?

Risk of Autism Spectrum Disorder in Offspring Without Family History

For couples with no personal or family history of autism or genetic disorders, the baseline population risk of having a child with ASD is approximately 1-1.6% (1 in 60-160 children), which represents the general population prevalence. 1

Understanding Your Baseline Risk

The general population risk for ASD in the absence of any affected family members is relatively low:

• Population prevalence: Approximately 5.6 per 1,000 children (roughly 1 in 160-180) 1
• No elevated risk factors: When neither parent has ASD and there is no family history, your risk approximates this baseline population rate 1
• This is substantially lower than recurrence risks seen in families with an affected child (6-32% depending on family composition) 1

Why Genetic Testing Is Not Routinely Recommended for You

Without any clinical indicators, preconception genetic screening for ASD is not recommended because:

• ASD is genetically heterogeneous: Over the past decade, researchers have identified many genetic factors, but most are rare mutations with large effect that occur de novo (spontaneously) rather than being inherited 1
• No single predictive test exists: Unlike conditions such as fragile X syndrome or single-gene disorders, ASD involves complex interactions between multiple genes and environmental factors 1, 2
• Most cases arise spontaneously: The majority of genetic variants associated with ASD are not inherited from parents but occur as new mutations 1

When Genetic Evaluation Would Be Indicated

Genetic counseling and testing become relevant in specific scenarios:

• After a child is diagnosed with ASD: Chromosomal microarray (CMA) testing yields positive results in approximately 40% of affected children, helping identify specific genetic causes 1
• Family history of developmental disabilities: If either partner has relatives with intellectual disability, psychiatric disorders, or neurodevelopmental conditions, genetic counseling may be warranted 1
• Consanguinity: If you and your partner are blood relatives, recessive genetic conditions become more likely 1
• Specific ethnic backgrounds: Certain populations have higher carrier rates for specific genetic conditions 3

Important Caveats About Risk Assessment

Several factors can modify risk even in families without obvious history:

• Parental age: Advanced parental age (particularly paternal) has been associated with slightly increased ASD risk, though this represents a modest elevation from baseline 2
• Environmental factors: Non-genetic factors also contribute to ASD risk, though specific modifiable factors remain poorly defined 2, 4
• Unrecognized family history: Some relatives may have milder presentations (such as social communication difficulties, ADHD, or anxiety) that represent the broader autism phenotype but were never formally diagnosed 1

What This Means for Your Family Planning

You can proceed with conception with reassurance that your risk is at the general population baseline:

• No preconception testing needed: Routine genetic screening for ASD is not indicated or available for couples without risk factors 1
• Standard prenatal care: Follow routine prenatal screening recommendations for chromosomal abnormalities (which may occasionally be associated with ASD) 1
• Developmental surveillance: After birth, ensure your child receives recommended developmental screening at 18 and 24 months, which allows for early identification and intervention if concerns arise 5

If ASD Is Diagnosed in Your Future Child

Should your child be diagnosed with ASD, genetic evaluation would then be recommended:

• Chromosomal microarray testing: This should be performed in all children diagnosed with ASD, with a diagnostic yield of approximately 40% 1
• Specific gene testing: Depending on clinical features, testing for fragile X syndrome (in males), MECP2 mutations (in females with specific features), or PTEN mutations may be indicated 1
• Recurrence risk counseling: If a genetic cause is identified, this provides specific information about risks for future pregnancies; if no cause is found, empirical recurrence risks of 6-10% would apply 1
• Clinical exome sequencing: May be considered if initial testing is negative, with an additional diagnostic yield of 15-25% 1

The Bottom Line

Your risk of having a child with ASD is the same as the general population (approximately 1-1.6%), and no preconception genetic testing is recommended or would meaningfully change this risk. 1 The vast majority of ASD cases occur in families with no prior history, arising from complex genetic and environmental interactions that cannot currently be predicted or prevented. 1, 2, 4