Genetic Counseling

Basics & Goals - Gene Chat 101

• Definition: Communication process addressing human problems associated with the occurrence, or risk, of a genetic disorder in a family.
• Core Aim: Help individuals/families:
  • Comprehend medical facts: diagnosis, prognosis, management.
  • Understand inheritance patterns & recurrence risk.
  • Explore options for dealing with risk (e.g., testing, prevention).
  • Choose a course of action aligned with their values.
  • Adjust to the condition or risk.
• Key Principles: Patient autonomy, informed consent, confidentiality, non-directive approach.

⭐ Genetic counseling is fundamentally non-directive, empowering individuals to make personal choices based on comprehensive information and their own values.

Indications - Referral Radar

📌 Mnemonic: "3 Ps" for referral timing: Pre-conception, Prenatal, Postnatal.

• Pre-conceptional:
  • Adv. maternal (>35)/paternal (>40) age
  • Prev. child: genetic dx, anomaly, ID
  • Family Hx: genetic condition
  • Consanguinity (1st/2nd deg.)
  • Rec. preg. loss (≥2-3)
  • Known carrier (thal, SCA)
  • Teratogen exposure (pre-concept.)
• Prenatal:
  • Abn. prenatal screen (NT, markers, NIPT)
  • Fetal anomalies (USG)
  • Mat. illness (DM, AEDs)/TORCH
  • Parental anxiety (genetic risk)
• Postnatal:
  • Dysmorphism, mult. cong. anomalies
  • DD/ID/ASD
  • Suspected IEM
  • Sensory loss (hearing/vision)
  • Positive NBS
  • Progressive neuro disorder
  • Ambiguous genitalia

⭐ Consanguinity significantly increases the risk of autosomal recessive disorders; counseling is crucial even with no prior family history.

Process & Pedigree - Guidance Pathway

• Primary Goal: Empower individuals/families with genetic risk understanding for informed, autonomous decisions.
• Structured Process:
  • Comprehensive History: Collect detailed medical, family (minimum 3 generations), and psychosocial information.
  • Pedigree Construction & Analysis:
    • Visually map family history using standard symbols (□ male, ○ female, ■/● affected).
    • Crucial for identifying mode of inheritance (e.g., AD, AR, X-linked).
  • Risk Calculation & Interpretation: Determine recurrence probabilities for family members; explain significance.
  • Information Disclosure & Options: Discuss diagnosis, natural history, prognosis, management, and available testing (e.g., PND).
  • Supportive Counseling: Address emotional, ethical, social impacts; facilitate shared decision-making.
  • Summary & Follow-up: Provide a written summary, offer resources, and plan ongoing support.

⭐ A detailed 3-generation pedigree is the cornerstone of genetic risk assessment.

ELSI & Testing - Lab Lowdown & Law

• Ethical, Legal, Social Implications (ELSI):
  • Informed Consent: Voluntary, non-directive; explain procedures, risks, benefits, limitations.
  • Confidentiality & Privacy: Strict protection of genetic data.
  • Autonomy: Patient's right to know/not know results.
  • Non-Discrimination: Prevent genetic bias (employment, insurance).
• Common Genetic Tests:
  • Karyotyping: Chromosomal abnormalities (e.g., Trisomy 21).
  • FISH: Microdeletions/duplications (e.g., DiGeorge syndrome).
  • CMA (Chromosomal Microarray): Detects copy number variations (CNVs).
  • NGS (Next-Generation Sequencing): Gene panels, exome/genome sequencing.
• Key Legislation:
  • PCPNDT Act, 1994: Prohibits pre-natal sex determination.

⭐ The PCPNDT Act is crucial for preventing sex-selective abortions and misuse of prenatal diagnostic techniques in India.

High‑Yield Points - ⚡ Biggest Takeaways

• Indications include advanced maternal age (>35 years), positive family history, consanguinity, and recurrent abortions.
• Core components are risk assessment, discussing inheritance, prognosis, and available options.
• Non-directive approach is essential, empowering informed patient decisions.
• Pre-conceptional counseling is vital for known carriers or affected individuals.
• Ethical issues like confidentiality, informed consent, and non-maleficence are central.
• Calculating recurrence risk (e.g., 25% for autosomal recessive conditions) is fundamental.