Schindler disease type 1

Schindler Disease Type 1: A Rare Neurodegenerative Disorder

Schindler disease type 1, also known as the infantile type, is the most severe form of Schindler disease. Babies with this condition appear healthy at birth but by the age of 8 to 15 months, they stop developing new skills and begin losing skills they had already acquired [4]. This rapid neurodegenerative course results in severe developmental delay, regression, blindness, seizures, and eventually loss of awareness of their surroundings and becoming unresponsive [13].

Infants with Schindler disease type 1 develop normally until about a year old, after which they experience a decline in cognitive and motor skills [9]. This condition is caused by mutations in the NAGA gene, leading to alpha-N-acetylgalactosaminidase deficiency type 1 [5].

Schindler disease type 1 is characterized by normal development for the first 9–15 months of life, followed by a rapid neurodegenerative course resulting in severe developmental delay and regression [7]. This condition is extremely rare, with an estimated prevalence of less than 1 in 1 million [3].

In summary, Schindler disease type 1 is a severe form of the disorder that affects infants, causing them to stop developing new skills and lose previously acquired ones. It is caused by mutations in the NAGA gene and is characterized by rapid neurodegeneration.

References:

[3] ORPHA:79279 [4] Context result 4 [5] Context result 5 [7] Context result 7 [9] Context result 9 [13] Context result 13

Severe Neurological Symptoms

Schindler disease type 1, also known as infantile Schindler disease, is the most severe form of this disorder. Babies with this condition appear healthy at birth but begin to show signs of regression in skills around 8-15 months of age.

• Rapid Regression: Between approximately 8-15 months, there is a rapid and severe regression in skills, including mental and physical development.
• Severe Mental Retardation: Individuals with infantile Schindler disease usually have severe mental retardation.
• Blindness: Many affected individuals are born blind or become blind at an early age.
• Seizures: Seizures are a common symptom of Schindler disease type 1.

Other Symptoms

In addition to the above symptoms, individuals with Schindler disease type 1 may also experience:

• Muscle Weakness: Muscle weakness and hypotonia (low muscle tone) are often present.
• Vision Loss: Vision loss or blindness can occur due to damage to the optic nerve.
• Developmental Delay: Developmental delay is a common feature, with affected individuals failing to reach developmental milestones.

Prognosis

The prognosis for Schindler disease type 1 is generally poor, with most affected individuals experiencing severe and lifelong disabilities. The severity of symptoms can vary, but in general, the earlier the diagnosis, the better the chances of managing the condition and improving quality of life.

References:

• [3] Schindler disease type II, also called Kanzaki disease, is a milder form of the disorder that usually appears in adulthood.
• [13] Schindler disease is an inherited condition that primarily causes neurological problems. There are three types of Schindler disease. Schindler disease type 1, also called the infantile type, is the most severe form.Babies with this condition appear healthy a birth, but by the age of 8 to 15 months they stop developing new skills and begin losing skills they had already acquired.
• [14] This cell damage in the nervous system and other tissues and organs in the body lead to the symptoms present in Schindler disease. There are three types of Schindler disease. Type I, also called infantile type is the most severe form and symptoms usually show around the age of 8-15 months.
• [15] Schindler Disease type I – also called infantile Typically, normal mental and physical development occurs during the first months of life. Between approximately 8–15 months, there is a rapid and severe regression in skills. Individuals with infantile Schindler disease usually have severe mental retardation, blindness, and/or seizures.

Diagnostic Tests for Schindler Disease Type 1

Schindler disease type 1, also known as infantile-onset neuroaxonal dystrophy, is a rare lysosomal storage disorder that can be diagnosed through various diagnostic tests. The diagnosis of this condition can be confirmed through molecular genetic testing by identifying mutations in the NAGA gene.

• Molecular Genetic Testing: This test involves sequencing analysis of the entire coding region to identify mutations in the NAGA gene. It is a next-generation sequencing (NGS) test that is appropriate for individuals with clinical signs and symptoms, suspicion of, or family history of Schindler disease type 1 [5][7].
• Prenatal Diagnosis: Prenatal diagnosis can be performed through molecular testing of the fetus during pregnancy. This may involve genetic testing of the expecting parents (and related family members) to understand the risks better during pregnancy [13].

Other Diagnostic Tests

While not specifically mentioned in the context, other diagnostic tests such as clinical trials and research studies may also be relevant in understanding Schindler disease type 1.

• Clinical Trials: Clinical trials determine if a new test or treatment for a disease is effective and safe by comparing it with existing treatments [12].
• Research Studies: Research studies may provide additional information on the diagnosis, treatment, and management of Schindler disease type 1.

References

[5] Molecular genetic testing can confirm a diagnosis of Schindler disease and help identify specific gene mutations. [7] This is a next-generation sequencing (NGS) test appropriate for individuals with clinical signs and symptoms, suspicion of, or family history of Schindler disease type 1. [12] Clinical trials determine if a new test or treatment for a disease is effective and safe by comparing it with existing treatments. [13] Genetic testing of the expecting parents (and related family members) and prenatal diagnosis may help in understanding the risks better during pregnancy.

Differential Diagnosis of Schindler Disease Type I

Schindler disease type I, also known as infantile neuroaxonal dystrophy, is a severe form of the disease that affects infants and young children. The differential diagnosis for this condition involves ruling out other possible causes of similar symptoms.

• Infantile Neuroaxonal Dystrophy: This is a rare genetic disorder characterized by progressive degeneration of neurons in the brain, leading to severe intellectual disability, nystagmus (uncontrolled eye movements), and other neurological symptoms. [4]
• Kanzaki Disease: Also known as Schindler disease type II, this condition shares similar symptoms with infantile neuroaxonal dystrophy but typically presents later in childhood or adolescence. [7]

When diagnosing Schindler disease type I, it is essential to consider these conditions and rule them out through a combination of clinical evaluation, laboratory tests, and genetic analysis.

Key Points:

• Infantile neuroaxonal dystrophy is a severe form of Schindler disease that affects infants and young children.
• Differential diagnosis involves ruling out other possible causes of similar symptoms, such as Kanzaki disease.
• A comprehensive diagnostic approach, including clinical evaluation, laboratory tests, and genetic analysis, is necessary to accurately diagnose Schindler disease type I.

References:

[4] Dec 27, 2023 — DI 23022.890 Schindler Disease -- Type I [7] It is clinically heterogeneous with 3 main phenotypes: type I is an infantile-onset neuroaxonal dystrophy; type II, also known as Kanzaki disease (609242), is ...