Glossary of Terms
A
ADHD (Attention Deficit Hyperactivity Disorder)
A neurodevelopmental condition affecting attention, impulse control, and activity levels. ADHD is highly prevalent in individuals with TSC (30–50%) and forms part of TAND. It may co-exist with epilepsy and intellectual disability, requiring careful management of medications.
ERN (European Reference Network)
European Reference Networks are virtual networks of specialised hospitals across the EU, set up in 2017 under the EU's cross-border healthcare directive, to pool expertise on rare and complex diseases that no single country has enough patients or specialists to manage well alone.
TAND-L (TAND Lifetime Checklist)
It's an interview-based tool, designed to be administered by a clinician with the individual with TSC and/or their family, capturing whether various TAND manifestations have ever been present over the person's lifetime.
HSE (Health Service Executive)
Ireland’s public health service.
AML (Angiomyolipoma)
A benign tumour made up of blood vessels, smooth muscle, and fat, most commonly affecting the kidneys in TSC (70–80% of patients). AMLs can grow and bleed, requiring monitoring or treatment (e.g. mTOR inhibitors or embolisation).
ASD (Autism Spectrum Disorder)
A neurodevelopmental condition affecting communication, behaviour, and social interaction. Up to 69% of individuals with TSC may meet criteria for ASD. Early diagnosis improves outcomes.
HRB (Health Research Board)
This is Ireland's lead public funding agency supporting innovative health research and delivering data and evidence that improves people's health and patient care, investing more than €50 million each year in health and social care research.
Autosomal Dominant
A genetic inheritance pattern where only one altered copy of a gene (TSC1 or TSC2) is required to cause TSC. Each child of an affected parent has a 50% chance of inheriting the condition.
Autosomal (General)
Refers to genes located on non-sex chromosomes, meaning the condition affects males and females equally.
C
CAMHS (Child & Adolescent Mental Health Services)
CAMHS is the HSE's designated service for young people up to age 18 with suspected or diagnosed significant mental health disorders, delivered by multidisciplinary community teams. For a child with TSC, CAMHS would generally become relevant when TAND features cross into what looks like a standalone psychiatric presentation.
Cardiac Rhabdomyoma (cRHM)
A benign tumour of the heart, often detected during pregnancy or infancy. It is one of the earliest indicators of TSC and often regresses naturally over time.
B
Benign Tumour
A non-cancerous growth that does not spread but may still cause problems depending on location. In TSC, benign tumours can occur in multiple organs including brain, kidneys, heart, lungs, and skin.
De Novo Mutation (Sporadic Mutation)
A new genetic mutation occurring for the first time in a child, without being inherited from either parent. Around two-thirds of TSC cases arise this way.
Cortical Tuber
A disorganised area of brain tissue found in the cerebral cortex. These lesions are strongly associated with epilepsy, developmental delay, and cognitive differences in TSC.
D
Dental Enamel Pits
Small defects in the enamel of teeth commonly seen in individuals with TSC. They are usually harmless but can assist in diagnosis.
CT (Computed Tomography)
A disorganised area of brain tissue found in the cerebral cortex. These lesions are strongly associated with epilepsy, developmental delay, and cognitive differences in TSC.
E
EEG (Electroencephalogram)
A test that measures electrical activity in the brain and is used to diagnose and monitor epilepsy in TSC.
Epilepsy
A neurological condition characterised by recurrent seizures. It affects up to 90% of individuals with TSC and is often one of the earliest clinical features.
Everolimus (mTOR Inhibitor)
A targeted therapy used to treat TSC-related tumours (e.g. SEGA, AML) and sometimes epilepsy by inhibiting the mTOR pathway.
G
GP (General Practitioner)
A GP is a medical doctor who provides primary medical care in Ireland, serving as the first point of contact for patients seeking health services. They care for individuals at all stages of life, addressing a wide range of health issues.
H
Hamartoma
A benign, tumour-like growth made up of disorganised but normal tissue elements. TSC is characterised by widespread hamartomas.
Hamartin-Tuberin Complex
Proteins produced by the TSC1 and TSC2 genes that regulate cell growth via the mTOR pathway. Dysfunction leads to uncontrolled growth and tumour formation.
Hydrocephalus
Proteins produced by the TSC1 and TSC2 genes that regulate cell growth via the mTOR pathway. Dysfunction leads to uncontrolled growth and tumour formation.
I
Infantile Spasms (IS)
A severe form of epilepsy occurring in infancy, commonly associated with TSC. Early treatment (often with vigabatrin) is critical.
Intellectual Disability (ID)
A condition involving limitations in intellectual functioning and adaptive behaviour. It can range from mild to severe in TSC.
IRDiRC (International Rare Disease Research Consortium)
This is one level up from ERNs: it's not a clinical care network but a global research-coordination body
L
LAM (Lymphangioleiomyomatosis)
A progressive lung disease affecting mainly women with TSC, caused by abnormal smooth muscle cell growth in the lungs.
M
MRI (Magnetic Resonance Imaging)
A detailed imaging technique using magnetic fields to visualise internal organs, particularly important for brain and kidney monitoring in TSC.
mTOR Pathway
A cellular signalling pathway that regulates growth and metabolism. Over activation due to TSC mutations leads to tumour formation.
mTOR Inhibitors (Rapalogs)
Medications such as everolimus and sirolimus that suppress abnormal cell growth in TSC by targeting the mTOR pathway.
Multidisciplinary Team (MDT)
A coordinated group of specialists (neurology, nephrology, dermatology, psychiatry, etc.) providing comprehensive TSC care.
P
Phakomatosis
A group of genetic disorders (including TSC) characterised by abnormalities in the skin, brain, and eyes.
R
Retinal Hamartoma (Phakoma)
A benign tumour on the retina that may affect vision but is often asymptomatic.
Renal (Kidney-related)
Refers to the kidneys. Renal complications such as AML are a major concern in TSC.
S
SEGA (Subependymal Giant Cell Astrocytoma)
A slow-growing brain tumour that can block cerebrospinal fluid flow and cause hydrocephalus. Requires monitoring and sometimes surgery or medication.
SEN (Subependymal Nodule)
Small benign growths along the brain ventricles that may develop into SEGA.
Seizure
A sudden burst of abnormal electrical activity in the brain. Seizure types vary widely in TSC.
Shagreen Patch
A thickened, leathery patch of skin, typically found on the lower back. A classic dermatological sign of TSC.
Surveillance
Lifelong monitoring using imaging and clinical review to detect complications early and guide treatment.
T
TAND (TSC-Associated Neuuropsychiatric Disorders)
An umbrella term covering cognitive, behavioural, psychiatric, academic, and psychosocial difficulties experienced by up to 90% of individuals with TSC.
TAND-SQ (Self-report Quantified TAND Checklist)
A self-report/caregiver-report tool (no clinician needed to administer it) and it's quantified. This means it produces numeric scores rather than just yes/no presence of symptoms.
TSC (Tuberous Sclerosis Complex)
A rare, multisystem genetic condition caused by mutations in TSC1 or TSC2, leading to benign tumours in multiple organs.
TSC1 Gene
Located on chromosome 9, this gene produces hamartin, a protein that regulates cell growth.
TSC2 Gene
Located on chromosome 16, this gene produces tuberin, which works with hamartin to suppress tumour formation.
U
Ungual Fibroma (Koenen’s Tumour)
Small benign growths around or under fingernails or toenails, often appearing in adolescence or adulthood.
V
Variable Expressivity
The degree to which TSC symptoms vary between individuals, even within the same family.
Vigabatrin
A first-line anti-seizure medication used particularly for infantile spasms in TSC.