Symptoms, Manifestations, and Progression

Because TSC2/PKD1 contiguous gene deletion syndrome affects two distinct genetic pathways, it presents a “dual phenotype”—meaning it carries symptoms of both Tuberous Sclerosis Complex (TSC) and Autosomal Dominant Polycystic Kidney Disease (ADPKD) ^[1][2]. While every journey is unique, the combination of these conditions often leads to earlier and more pronounced symptoms than when either condition occurs alone.

Renal (Kidney) Manifestations

For many families, the first sign of the syndrome is found in the kidneys, sometimes even before a child is born.

• Early-Onset Cysts: Unlike typical TSC, where kidney cysts are often small and appear later, individuals with this deletion syndrome frequently show enlarged, cystic kidneys on prenatal ultrasounds or during early infancy ^[3][4].
• Kidney Enlargement: The kidneys can become significantly larger than normal as they fill with numerous fluid-filled sacs ^[2]. In some children, this enlargement is noticeable to a doctor during a physical exam ^[5].
• Hypertension (High Blood Pressure): This is a critical early symptom that can emerge in infancy or early childhood ^[6][4]. Hypertension in cystic kidney disease involves altered renal blood flow and complex hormonal signaling (the renin-angiotensin-aldosterone system), as well as physical compression from growing cysts.
• Angiomyolipomas (AMLs): These are benign tumors made of fat, muscle, and blood vessels that are common in TSC ^[7]. In this syndrome, they can appear alongside the cysts, further increasing the size of the kidneys ^[2].

Neurological and Systemic Features

The involvement of the TSC2 gene means that many of the standard features of Tuberous Sclerosis Complex are also present.

• Seizures and Infantile Spasms: Seizures are common and often begin in the first year of life ^[3][6]. This can include infantile spasms, a specific type of seizure that looks like sudden stiffening or “jackknife” movements, which require urgent medical attention ^[6].
• Brain Lesions: Individuals may have cortical tubers (small areas of different brain structure) and subependymal nodules (small growths near the brain’s fluid spaces) ^[2]. A portion of patients may develop subependymal giant cell astrocytomas (SEGA), which are benign brain tumors that can grow and require monitoring via MRI ^[8].
• Skin Findings: These are often the most visible signs of TSC and can include hypomelanotic macules (pale, “ash-leaf” shaped spots), facial angiofibromas (small, reddish bumps on the face), and shagreen patches (areas of thickened, leathery skin) ^[3][8].
• Other Organ Lesions: Infants may have cardiac rhabdomyomas (benign heart tumors that often regress over time). Later in life, individuals may develop retinal hamartomas (eye lesions) or hepatic (liver) cysts and AMLs ^[9][2]. It is important to note that significant lung involvement, such as Lymphangioleiomyomatosis (LAM), is predominantly an adult condition seen in women, not a routine childhood presentation.

TSC-Associated Neuropsychiatric Disorders (TAND)

TAND is an “umbrella term” used to describe the wide range of behavioral, psychiatric, and intellectual challenges that can accompany TSC ^[10]. Because these symptoms are not always visible on a scan, they are often underdiagnosed. TAND may include:

• Developmental and Intellectual Disability: This can range from mild learning difficulties to more significant intellectual challenges ^[10][11].
• Autism and ADHD: Features of Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) are common in the TSC population ^[10].
• Behavioral Concerns: Parents may notice anxiety, mood swings, sleep disruptions, or aggressive behaviors ^[10][12].
• Academic Struggles: Difficulties with memory, attention, or specific school subjects are frequently reported ^[10].

Understanding Disease Progression

One of the most important things to know is that while the kidney disease is more pronounced than in typical TSC, there is no dependable, single timeline for progression.

The progression of kidney disease is highly heterogeneous (variable). You may read that the median age for reaching End-Stage Kidney Disease (ESKD) in some small, selected case series is in the early 20s ^[13][3]. However, these small studies may not represent all affected individuals under current medical care. Individual risk cannot be predicted simply by age; it is better assessed by a nephrologist tracking trends in blood pressure, proteinuria (protein in the urine), kidney structure/volume, and eGFR (estimated glomerular filtration rate) over time ^[4][14].