Neurotransmitters Module: The Beery Twins’ Story©

A Project-Based Learning Activity

Captivate your students and cover a wide range of science topics with the true story of California twins Noah and Alexis Beery, who have gene variants that cause them to have life-threatening low levels of three neurotransmitters. Whole genome sequencing in 2010 identified a mutation in the gene that encodes the sepiapterin reductase (SPR) enzyme, leading to a molecular diagnosis and successful treatment.

Human Sepiapterin Reductase mRNA Gene Map©

A 3DMD BioInformatics Activity©

This gene map presents the nucleotide sequence of the messenger RNA encoding sepiapterin reductase - the enzyme that was shown to be defective in Noah and Alexis Beery. The map documents the molecular consequence of two different mutations in this gene that were responsible for the neurotransmitter deficiencies experienced by the Beery twins. Student maps can be used by individuals or small groups and are available in sets of 1, 3 or 6. One teacher's map comes with every set. The teacher’s map features highlighted reading frames and mutation sites. All maps are laminated. 

Sepiapterin Reductase Mini Model

Show your students a physical representation of the twins' genetic mutations and neurotransmitter deficiencies. Three small, magnet-docked sections of our Sepiapterin Reductase Mini Model are removable, revealing the two mutations that the twins inherited from their parents and the cofactor needed for the production of the neurotransmitters.

Dopamine and Serotonin Biosynthesis Models

These models show how two amino acids (tyrosine and tryptophan) are converted into two neurotransmitters (dopamine and serotonin) by two consecutive enzyme-catalyzed reactions. Magnet-docked hydroxyl groups, carboxylate groups and hydrogens allow each model to be quickly converted from amino acid to neurotransmitter in two easy steps. These structures were determined with the National Institute of Health databank.

Models are made of plaster by 3-D printing and should be handled with care. They will break if dropped, held tightly or handled roughly.

Human SPR mRNA Gene Map Teacher Notes

The activity guide for the Human Sepiapterin Reductase mRNA Gene Map© will help you consider different ways you may use these materials. We encourage you to modify these lessons and activities to meet the learning objectives and needs of your specific students.

Dopamine and Serotonin Biosynthesis Placemats

Use these placemats with the Dopamine and Serotonin Biosynthesis Models to guide your students through the conversion of the amino acids tyrosine and tryptophan into the neurotransmitters dopamine and serotonin.

Human SPR mRNA Gene Map Student Handout 1 and Key

What does the Beery family's pedigree reveal about their medical history?

Neurotransmitters Module Additional Resources

A list of some excellent resources to help you make the most of the Neurotransmitters Module's lessons and activities.

Human SPR mRNA Gene Map Student Handout 2 and Key

Have your students work through this handout and the gene map together, to answer questions about genome sequencing, the sepiapterin reductase enzyme, mutations and amino acids, and genetics.

Neurotransmitters Module Next Generation Science Standards

Human SPR mRNA Gene Map Connections to: A Framework for K-12 Science Education Practices, Crosscutting Concepts, and Core Ideas

Human SPR Placemat

This placemat provides a concise scientific account of the Beery twins' story and molecular diagnosis through whole genome sequencing.

Product Details

Grade Level

High School

Students per Group



Choking Hazard
Small Magnets
Science Education Product
California Proposition 65

List Price

1 Student and 1 Teacher SPR mRNA Gene Maps           $29 (SPRGM-01S-01T)

3 Student and 1 Teacher SPR mRNA Gene Maps           $49 (SPRGM-03S-01T)

6 Student and 1 Teacher SPR mRNA Gene Maps           $79 (SPRGM-06S-01T)

Sepiapterin Reductase Mini Model    $137 (SPRMM)

3'' Dopamine Biosynthesis Model      $37 (DBMM)

3'' Serotonin Biosynthesis Model      $39 (SBMM)


Teacher Tip

The gene map and biosynthesis models may be purchased and used separately or together to meet the needs of your classroom.

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