Family history of possible genetic disorder

Autosomal Dominant Disorders

Huntington’s Disease: Progressive neurodegenerative disorder with family history of similar symptoms; usually presents in mid-adulthood.
Marfan Syndrome: Tall stature, long limbs, lens dislocation, and aortic aneurysms; family history of similar physical features or sudden cardiac death.
Familial Hypercholesterolemia: Early-onset cardiovascular disease, xanthomas, and a family history of hypercholesterolemia or premature myocardial infarction.
Neurofibromatosis Type 1: Multiple café-au-lait spots, neurofibromas, and family history of similar skin lesions or neurological symptoms.
Polycystic Kidney Disease: Bilateral renal cysts, hypertension, and family history of renal failure or cystic kidneys.
Hereditary Breast and Ovarian Cancer Syndrome (BRCA1/2): Family history of breast, ovarian, or prostate cancer; often presents at a younger age.

Autosomal Recessive Disorders

Cystic Fibrosis: Chronic respiratory infections, pancreatic insufficiency, and a family history of similar symptoms in siblings.
Sickle Cell Disease: Recurrent pain crises, hemolytic anemia, and family history of similar blood disorder in siblings or parents.
Tay-Sachs Disease: Progressive neurodegeneration in infancy, developmental delay, and family history of early childhood deaths, particularly in specific ethnic groups.
Thalassemia: Microcytic anemia unresponsive to iron, often with a family history of anemia or hemoglobinopathy.
Phenylketonuria: Intellectual disability if untreated, with a family history of developmental delay or consanguinity.
Congenital Adrenal Hyperplasia: Ambiguous genitalia, salt-wasting crises in infancy, and a family history of similar symptoms or neonatal deaths.

X-Linked Disorders

Duchenne Muscular Dystrophy: Progressive muscle weakness in boys, often with a family history of similar symptoms in male relatives.
Fragile X Syndrome: Intellectual disability, particularly in males, with family history of learning difficulties or autism.
Hemophilia: Tendency to bleed with minor trauma, often with a family history of bleeding disorders in male relatives.
G6PD Deficiency: Hemolytic anemia, particularly after certain triggers like fava beans or certain drugs, with family history of similar episodes.
Rett Syndrome: Neurodevelopmental disorder in females, with loss of motor skills and communication; often no family history due to de novo mutations.

Multifactorial Inheritance

Type 2 Diabetes: Strong family history of diabetes, particularly in the presence of obesity and metabolic syndrome.
Ischaemic Heart Disease: Family history of early onset myocardial infarction or stroke, particularly with associated risk factors like hyperlipidemia.
Neural Tube Defects: Family history of spina bifida or anencephaly, with environmental risk factors such as folate deficiency.
Hypertension: Family history of hypertension, often with clustering of cardiovascular risk factors like diabetes and hyperlipidemia.
Asthma: Family history of asthma, allergies, or atopic conditions, often with environmental triggers.
Schizophrenia: Increased risk with a family history of schizophrenia or other psychiatric disorders.

Family History

Pattern of Inheritance: Ask about similar conditions in first-degree, second-degree, and extended family members to identify potential inheritance patterns.
Age of Onset: Early onset of symptoms in relatives may suggest a genetic component, particularly in conditions like cancer or cardiovascular disease.
Ethnicity: Some genetic conditions are more prevalent in certain ethnic groups (e.g., sickle cell disease in Afro-Caribbean populations, Tay-Sachs in Ashkenazi Jews).
Consanguinity: Ask about consanguinity, as it increases the risk of autosomal recessive disorders.
Unexplained Deaths: History of sudden, unexplained deaths in the family may suggest an inherited condition such as arrhythmogenic right ventricular cardiomyopathy (ARVC) or Long QT syndrome.
Recurrent Miscarriages or Stillbirths: May indicate an underlying genetic or chromosomal disorder.

Background

Past Medical History: Note any personal history of symptoms that could suggest a genetic disorder, such as developmental delays, recurrent infections, or unusual physical features.
Drug History: Some genetic conditions can influence drug metabolism (e.g., G6PD deficiency and sulfa drugs), or drug effects can unmask latent conditions.
Social History: Family structure, including number of siblings and any known family relationships (consanguinity), may offer clues to inheritance patterns.
Reproductive History: Details of any pregnancies, miscarriages, or stillbirths may be relevant in assessing genetic risk.

Genetic Testing

Targeted Gene Testing: For specific conditions based on family history, such as BRCA testing in families with a history of breast and ovarian cancer.
Whole Exome Sequencing: Used when a specific genetic condition is suspected but not confirmed, particularly in cases with multiple congenital anomalies or complex syndromes.
Carrier Screening: Particularly for autosomal recessive conditions in high-risk populations or in consanguineous couples planning a family.
Preimplantation Genetic Diagnosis (PGD): Used in IVF to test embryos for specific genetic conditions before implantation.
Prenatal Testing: Amniocentesis or chorionic villus sampling (CVS) to detect chromosomal abnormalities or genetic disorders in a fetus.
Newborn Screening: Routine tests for certain genetic conditions in newborns, such as cystic fibrosis or phenylketonuria.

Imaging and Other Tests

Echocardiogram: Useful in diagnosing Marfan syndrome or other connective tissue disorders with cardiovascular involvement.
MRI/CT Scan: Imaging may be indicated to assess for structural abnormalities in conditions like neurofibromatosis or tuberous sclerosis.
Electrocardiogram (ECG): To screen for arrhythmias in conditions such as Long QT syndrome or hypertrophic cardiomyopathy.
Ophthalmological Examination: Slit-lamp examination for lens dislocation in Marfan syndrome, or retinal changes in retinoblastoma.
Biopsy: Skin or muscle biopsy may be indicated for conditions like muscular dystrophy or metabolic storage diseases.
Metabolic Screening: Blood and urine tests to screen for inborn errors of metabolism, such as amino acidopathies or organic acidemias.

Cancer