Genetics and Nutrition Quiz

Heel Prick Test

• All newborn babies in Ireland are screened for six rare conditions via the Heel Prick Test
• The Heel Prick Test involves taking a small blood sample from the baby's heel
• The screening ensures that any babies with rare conditions are identified and treated as early as possible

Autosomal Recessive Genetic Disorders

• A child affected with an autosomal recessive genetic disorder has two parents who carry the recessive gene
• Unaffected siblings may still carry the recessive gene
• Each pregnancy has a 25% chance of having a child with the condition

Macronutrients

• Protein is a building block for the body. Sources include meat, chicken, fish, eggs, legumes, and cheese.
• Carbohydrate is an energy source. Sources include rice, potatoes, pasta, and cereals.
• Fat is an energy source. Sources include oils, butter, cream, and lard.

Amino Acids

• Amino acids are organic compounds that combine to form proteins
• Essential amino acids cannot be made by the body and need to be obtained through food
• Essential amino acids are building blocks of life and are used by the body:
  • To break down food
  • For growth
  • To repair body tissue
  • For many other body functions

Phenylketonuria (PKU)

• PKU is a rare genetic disorder that affects the way the body breaks down phenylalanine
• Phenylalanine is an amino acid found in protein
• If PKU is left untreated, it can lead to serious health problems, including:
  • Intellectual disability
  • Seizures
  • Behavioral problems
  • Skin problems

Dietary Management of PKU

• The aims of dietary treatment are to:
  • Reduce phenylalanine levels to 120-360 µmol/l 12years
  • Provide adequate protein, energy, vitamins and minerals for growth
  • Replace tyrosine and prevent deficiencies
  • Provide variety, palatability and flexibility to suit individual lifestyles

Types of Diet for PKU Management

• Dietary management for PKU consists of 3 components:
  • Natural Protein (Measured amounts of phenylalanine ): This is restricted in order to maintain optimum levels
  • Synthetic Amino Acid mixture (phenylalanine-free infant formula / drink): This is a manufactured protein source, usually in the form of a drink, and balances the child’s protein requirements
  • “Free Foods” & Vitamins and minerals: This refers to foods that are “free” from protein. Such foods are rich in carbohydrates and fat, but patients must avoid medications sweetened using Aspartame.

Galactosaemia

• Galactosaemia is a disorder of carbohydrate metabolism
• It is caused by a deficiency of an enzyme that metabolises the sugar galactose, which is present in lactose
• Signs and symptoms include:
  • Poor sucking reflex
  • Poor feeding and weight gain
  • Vomiting and diarrhea
  • Jaundice
  • Cataracts
  • Lethargy and hypotonia
  • Hepatomegaly
  • Coagulopathy
  • Susceptibility to infection, especially E. coli

Management of Galactosaemia

• A galactose-free diet for life is the only form of treatment. No dairy or milk derivatives, including breastfeeding, are permitted
• Untreated galactose accumulates in the brain, liver, kidneys, eyes and ovaries
• This can lead to:
  • Intellectual disability
  • Cirrhosis
  • Cataracts
  • Renal problems
  • Female infertility

History of Galactosaemia Screening

• The Beutler Test is used for immediate testing after birth
• The Beutler Test tests for enzyme activity in red blood cells and is independent of food intake
• Newborn screening sample taken 72-120 hrs after to detect other abnormalities.

High Incidence of Galactosaemia in Traveller Parents

• The incidence of this disorder is approximately 1 in 450 births among Traveller parents
• The incidence is approximately 1 in 36,000 births in the non-traveller Irish community

Nursing Care for Galactosaemia Patients

• General observations
• Neurological status
• TPR (temperature, pulse, respiration)
• Intake/output (Strict Calorie count)
• Diet
• Discontinue all natural protein-containing products
• Continue synthetic protein mixture (orally or via a nasogastric tube)
• On-going education
• Multidisciplinary management and support

Multidisciplinary Support

• Patients with Galactosaemia benefit from multidisciplinary support, including:
  • Metabolic clinic
  • Psychology
  • Social Work
  • Other (e.g., Neurology, Speech and Language therapy)

Mucopolysaccharide Diseases

• Mucopolysaccharides are long chains of sugar molecules used in the building of connective tissues in the body

Lysosomal Storage Disorders

• A group of genetic disorders in which harmful quantities of certain substances build up in various parts of the body

Signs & Symptoms of Lysosomal Storage Disorders

• General
  • Short stature
  • Coarse/distinctive facies
  • Enlarged adenoids/tonsils
  • Hepatosplenomegaly
  • Umbilical/inguinal hernia
• Bone & Joints:
  • Dysostosis multiplex
  • Odontoid hypoplasia
  • Dysplastic teeth
  • Joint stiffness & contractures
• Cardiopulmonary:
  • Obstructive airway disease
  • Sleep apnea
  • Cardiac valve regurgitation/stenosis

Inborn Errors of Metabolic Disorders (IEMs)

• IEMs are a group of inherited disorders that affect the body’s metabolism, the chemical process that breaks down food into energy
• IEMs can cause a wide range of symptoms, from mild to severe

Management of IEMs

• IEMs are typically managed through:
  • Dietary restrictions
  • Enzyme replacement therapy
  • Liver transplantation
  • Medications

Summary of Inborn Errors of Metabolic Disorders

• An understanding of the abnormality contributing to metabolic disorders
• The classification of Metabolic Disorders
• The management of a child with Metabolic Disorders

Test your knowledge on crucial topics such as the Heel Prick Test, autosomal recessive genetic disorders, macronutrients, and amino acids. This quiz will challenge your understanding of newborn screening, the genetic inheritance of disorders, and the role of various macronutrients in nutrition.