The PIND Study research database.

The database was originally an Access database used to record clinical information about children notified to the PIND Study.

It contains detailed data on presenting symptoms and signs in children with progressive intellectual and neurological deterioration (PIND), as well as records of all investigations carried out, including those key to making the final diagnosis.

Study Timeline
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Start date: **May 1997**

Notification Trends
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- **First 20 months:** Large number of prevalent cases
- **1999 to 2018:** 146 to 230 cases per year (stable rate despite COVID-19 disruption)
- **2019 to 2023:** 121 to 171 cases per year
- After active surveillance ended (end of 2023): 6 cases notified, last in April 2024

By April 2024 (after 27 years):

- **Total notifications:** 5,222 cases

Case Breakdown
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- 2,540 cases did not meet PIND definition (duplicates, reporting errors, or missing info)
- **PIND with no known diagnosis:** 309 cases
- **vCJD cases:** 6 cases (4 definite, 2 probable)
- **PIND with underlying diagnosis (excluding vCJD):** 2,367 cases

Lifetime Risk
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- Diagnosis period: **May 1997 to April 2024**
- UK live births (1997 to 2023): 19,598,293 births
- **Calculated risk:** 0.1 per 1,000 live births

Demographics
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Of the 2,367 diagnosed children (excluding vCJD):

- **Gender:** Male 1,265 cases | Female 1,102 cases
- **Ethnicity data (2,183 cases):**
- Asian or Asian British: 625 cases (28.6%)
- Indian: 60 cases
- Pakistani: 449 cases
- Bangladeshi: 54 cases
- Other Asian: 56 cases
- Chinese: 6 cases
- White: 1,342 cases (61.5%)
- Black: 72 cases (3.3%)
- Mixed: 67 cases (3.1%)
- Other: 77 cases (3.5%)

Comparison with 2021 Census (England and Wales):
- Asian groups: 9.3%
- White: 81.7%
- Black: 4.0%
- Mixed: 2.9%
- Other: 2.1%

**Observation:** Higher proportion of Asian British children in PIND study (28.6% vs census 9.3%)

Many PIND-causing diseases are autosomal recessive.
Consanguinity rates:
- Pakistani: 67%
- Bangladeshi: 48%
- Indian: 13%
- White: 3%

Investigations
--------------

**Neuropathology**
- Brain biopsies: 14 cases (helpful in 13 cases: white matter disorders, Rasmussen encephalitis, mitochondrial diseases, etc.)

**Molecular Genetics**
- Results available: 1,312 cases
- Diagnostic or confirmatory: 864 cases (66%)
- Trend: Increasing role over time
- 1997 to 2001: 32 cases diagnosed
- 2019 to 2023: 206 cases diagnosed

**Post Mortem**
- Known deaths: 1,338 cases
- Post mortem investigations: 39 cases (helpful in 25 cases)
- Brain tissue available in 23 cases (diagnoses included Alpers disease, mitochondrial disorders, leukodystrophies, etc.)

Disease Distribution
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- Total diagnosed diseases: 259 (excluding vCJD)
- Inborn errors of metabolism: 61% of diseases (78% of diagnosed children)

Major groups:
- Leukodystrophies: 444 cases
- Mitochondrial diseases: 364 cases
- Neuronal ceroid lipofuscinoses: 309 cases
- Lysosomal diseases: 971 cases

Conclusion
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The database is a unique resource for epidemiology and clinical features of more than 200 neurodegenerative childhood diseases.

Case series can be identified by searching for specific diagnoses.