molybdenum cofactor deficiency type B

Molybdenum cofactor deficiency (MoCD) type B is a rare and severe form of the disorder, typically presenting in infancy or early childhood.

• Symptoms often include intractable seizures, opisthotonus (a condition characterized by arching of the back), and feeding difficulties [4][7].
• The condition can also lead to severe developmental delay, microcephaly (small head size), and brain atrophy [10].
• In some cases, MoCD type B may present with a more gradual onset of symptoms, but the overall prognosis remains poor due to the severity of the condition [1][3].

It's worth noting that late-onset forms of MoCD, such as types A and B, tend to have milder symptoms beginning later in infancy or even adulthood. However, these forms still carry a significant risk of acute neurologic decompensation in the setting of infection [3].

Molybdenum cofactor deficiency (MoCD) Type B is a rare genetic disorder characterized by severe brain dysfunction, seizures, and other systemic symptoms. The signs and symptoms of MoCD Type B can vary in severity and may include:

• Neonatal-onset encephalopathy: Brain dysfunction that worsens over time, leading to severe developmental delay, seizures, and loss of vision [1][2].
• Seizures: Refractory seizures are a hallmark symptom of MoCD Type B, often appearing within the first week of life [9].
• Global developmental delay: Children with MoCD Type B experience significant delays in cognitive, motor, and language development [5].
• Facial features: Some children with MoCD have characteristic facial features, although this is not a universal finding [1].
• Opisthotonus: A condition characterized by an abnormal posture of the body, often seen in patients with severe brain dysfunction [8].

It's worth noting that MoCD Type B is a rare and severe disorder, and the symptoms can be quite variable. However, early recognition and diagnosis are crucial for providing appropriate medical care and management.

References: [1] Mar 1, 2014 — Molybdenum cofactor deficiency is a rare condition characterized by brain dysfunction (encephalopathy) that worsens over time. [2] by L Johannes · 2022 · Cited by 28 — Molybdenum cofactor (Moco) deficiency (MoCD) is characterized by neonatal-onset myoclonic epileptic encephalopathy and dystonia with cerebral MRI changes. [3] Mar 1, 2014 — Molybdenum cofactor deficiency is a rare condition characterized by brain dysfunction (encephalopathy) that worsens over time. [4] by M Nagappa · 2015 · Cited by 23 — The combination of severe global developmental delay, seizures, and dislocated ocular lenses is characteristic of MoCD and isolated sulfite ... [5] by Y Lin · 2021 · Cited by 9 — All patients with MOCS2 who develop symptoms in the newborn period have typical clinical feature: refractory seizures, neurological deterioration, facial ... [6] Children with MoCD Type A do not have symptoms at birth. But, within a few hours to a few days (sometimes longer), they often have trouble feeding and seizures ... [7] Molybdenum cofactor deficiency is a rare autosomal recessive metabolic disorder characterized by neonatal onset of intractable seizures, opisthotonus, ... [8] SIGNS AND SYMPTOMS · Babies with this condition can appear normal at birth. However, within a week they develop seizures. The seizures do not improve with ...

Molybdenum cofactor deficiency type B (MoCD-B) is a rare genetic disorder that can be diagnosed through various diagnostic tests.

Genetic Testing Genetic testing is the primary method for diagnosing MoCD-B. This involves analyzing the genes responsible for producing the molybdenum cofactor, specifically the MOCS2 gene. A biallelic pathogenic variant in this gene or significantly reduced activity of the enzyme sulfite oxidase in cultured fibroblasts can confirm the diagnosis [1][12].

Laboratory Tests In addition to genetic testing, laboratory tests are also used to diagnose MoCD-B. These include:

• Urine or blood test (biochemical test) that measures the levels of certain chemicals, such as sulfite, S-sulfocysteine, xanthine, and hypoxanthine [6][8][9].
• Plasma amino acids and serum uric acid tests to assess the biochemical profile of the patient [8].
• Mass spectrometry to detect S-sulfocysteine in urine [7].

Other Diagnostic Methods Prenatal diagnosis is also possible through assay of sulphite oxidase activity in chorionic villus samples [15]. However, false negative thiosulphate screening tests can occur in cases of MoCD-B [15].

It's worth noting that a characteristic biochemical profile permits early diagnosis of MoCD-B, and more than 100 genetically characterized patients have been reported [10][13].

References: [1] - Context result 2 [6] - Context result 9 [7] - Context result 7 [8] - Context result 8 [9] - Context result 9 [10] - Context result 10 [12] - Context result 12 [13] - Context result 13 [15] - Context result 15

Current Treatment Options for Molybdenum Cofactor Deficiency Type B

Unfortunately, there are no specific drug treatments approved by the FDA or other regulatory agencies to treat molybdenum cofactor deficiency (MoCD) type B. However, researchers have discussed biochemical principles that may require experimental testing for therapies targeting MoCD type B, type C, and iSOD [6].

Current Therapies Under Investigation

While there are no approved treatments for MoCD type B, ongoing research is focused on developing new therapeutic strategies to address this condition. These efforts aim to improve our understanding of the biochemical principles underlying MoCD type B and identify potential targets for intervention.

Comparison with Other Types of MoCD

It's worth noting that fosdenopterin (Nulibry) has been approved by the FDA to reduce the risk of mortality in patients with molybdenum cofactor deficiency (MoCD) Type A [4, 5]. However, this treatment is only effective for MoCD type A and not for other types, including type B.

Thiamine Supplementation

Interestingly, thiamine supplementation has been suggested as a potential therapeutic approach for certain conditions characterized by thiamine deficiency. However, its effectiveness in treating MoCD type B remains unclear [2].

Conclusion

In summary, while there are no approved drug treatments specifically targeting molybdenum cofactor deficiency type B, ongoing research is focused on developing new therapies to address this condition. Further investigation is needed to identify effective treatment options for patients with MoCD type B.

References:

[1] Not applicable (no relevant information found)

[2] Context 2: Thiamine supplementation (1.2 mg/day for infants; 50 mg/1x/day to 100 mg/2x/day for children/adolescents

Molybdenum cofactor deficiency (MoCD) type B is a rare inherited metabolic disorder caused by variants in the MOCS2 gene, which affects the formation of molybdenum cofactor. The differential diagnosis for MoCD type B involves considering other conditions that may present with similar symptoms.

Similar Conditions:

• Hypoxic-Ischemic Encephalopathy (HIE): This condition can cause similar brain dysfunction and MRI changes as seen in MoCD type B.
• Glycine Encephalopathy: A rare genetic disorder that affects the metabolism of glycine, leading to severe neurological symptoms.
• Pyridoxamine 5'-phosphate oxidase deficiency: A rare genetic disorder affecting the metabolism of vitamin B6, which can cause similar neurological symptoms.

Key Diagnostic Features:

• Neonatal-onset myoclonic epileptic encephalopathy and dystonia: These are characteristic features of MoCD type B.
• Cerebral MRI changes: Similar to HIE, but with distinct differences in the pattern of brain damage.
• Biochemical profile: A specific set of abnormal biochemical findings, such as high anion gap metabolic acidosis, ketonuria, or hyperammonemia.

Differential Diagnosis:

To establish a differential diagnosis for MoCD type B, it is essential to consider these similar conditions and their characteristic features. This can be achieved through:

• Clinical evaluation: A thorough medical history and physical examination.
• Imaging studies: MRI of the brain to assess for characteristic changes.
• Biochemical analysis: Measurement of specific biochemical markers in blood, urine, or cerebrospinal fluid.

References:

• [1] M Nagappa (2015) - Brain MRI should be used judiciously to distinguish MoCD from HIE.
• [4] M Nagappa (2015) - Severe cystic degeneration and atrophy of the brain are characteristic features of MoCD type B.
• [9] Abnormal biochemical findings such as high anion gap metabolic acidosis, ketonuria, or hyperammonemia, as well as dysmorphic features, liver disease, ...

Note: The numbers in square brackets refer to the corresponding references in the provided context.