autosomal dominant microcephaly

Autosomal dominant microcephaly refers to a rare genetic disorder characterized by an abnormally small head size, typically evident from early childhood. This condition can occur in isolation or in association with other malformations.

Key Features:

• Small head circumference, often below -2 SD from the mean for the infant's gestational age, sex, and ethnic origin [4][10]
• May appear as an isolated trait or in association with other malformations
• Can be sporadic or familial, with some cases being autosomal dominant [5]

Symptoms:

• Small head circumference apparent in early childhood
• Global developmental delay manifesting as delayed walking, inability to walk, impaired intellectual development, and poor or absent speech [3]
• Degree of intellectual dysfunction is not as severe as that recorded in autosomal recessive microcephaly [5]

Inheritance Pattern: Autosomal dominant primary microcephaly-27 (MCPH27) is a specific subtype characterized by small head circumference evident in early childhood and associated with global developmental delay. This condition follows an autosomal dominant inheritance pattern, meaning that a single copy of the mutated gene is sufficient to cause the disorder [3].

References:

• Haslam RH (1979) Four families with autosomal dominant microcephaly are reported. [1]
• Bawle E, Horton M (1989) Autosomal dominant microcephaly with mental retardation. Am J Med Genet 33:382-384. [4]
• Rossi LN (1987) Six Italian families affected by microcephaly with an apparently autosomal mode of inheritance. [8]

Note: The information provided is based on the search results and may not be comprehensive or up-to-date. If you need more detailed or specific information, please let me know!

Autosomal dominant microcephaly, also known as MCPH1, is a rare genetic disorder that affects brain development and leads to a small head size. The signs and symptoms of this condition can vary in severity and may include:

• Small head size: One of the main symptoms of autosomal dominant microcephaly is a significantly smaller head circumference compared to other children of the same age, sex, and ethnicity [12][14].
• Delayed cognitive development: Children with MCPH1 may experience delays in cognitive development, including issues with learning, memory, and problem-solving skills [13].
• Seizures: Seizures are a common symptom of autosomal dominant microcephaly, affecting about 10% of individuals with the condition [5][9].
• Delayed motor milestones: Children with MCPH1 may experience delays in reaching early motor milestones, such as sitting, standing, and walking [4][8].
• Speech delay: Speech development can also be delayed or impaired in children with autosomal dominant microcephaly [3][7].
• Hyperactive behavior: Some individuals with MCPH1 may exhibit hyperactive behavior, which can be a challenge for parents and caregivers to manage [5].

It's essential to note that each child with autosomal dominant microcephaly may experience symptoms differently, and the severity of these symptoms can vary widely. If you suspect your child has this condition, it's crucial to consult with a healthcare professional for proper evaluation and guidance.

References:

[3] Context result 4 [5] Context result 4 [7] Context result 6 [8] Context result 3 [9] Context result 9 [12] Context result 12 [13] Context result 13 [14] Context result 14

Autosomal dominant microcephaly, also known as primary microcephaly (MCPH), is a rare genetic disorder characterized by an abnormally small head size and intellectual disability. Diagnostic tests for autosomal dominant microcephaly are crucial in identifying the underlying cause of the condition.

Genetic Testing

• Exome Sequencing with CNV Detection: This test is ideal for patients with a clinical suspicion of microcephaly or pontocerebellar hypoplasias. It involves sequencing the entire exome (the protein-coding part of the genome) and detecting copy number variants (CNVs). [7]
• Chromosomal Microarray Analysis (CMA): CMA is a genetic test that can identify chromosomal abnormalities, including deletions or duplications, which may contribute to microcephaly. [9]

Other Diagnostic Tests

• PCR Testing: PCR testing of HSV-1 and HSV-2 in maternal serum can diagnose acute primary herpes simplex virus (HSV) infection, which is a rare cause of autosomal dominant microcephaly. [11]
• Immunoglobulin M (IgM) Antibody Test: This test detects the presence of IgM antibodies against HSV-1 or HSV-2, indicating an active infection. [11]

Clinical Genetic Tests

• Genetic Services Laboratory's Clinical Genetic Test: This test assesses genes associated with syndromes where microcephaly is a clinical feature, including Rett syndrome and Angelman syndrome. [5]
• Sequencing Test for ASPM-MCPH: This test evaluates the ASPM gene, which is commonly mutated in autosomal dominant primary microcephaly (ASPM-MCPH). [1]

Other Considerations

• Head Circumference Measurement: Measuring head circumference can help identify microcephaly. The measurement should be taken above the eyebrows and ears. [6]
• Clinical Evaluation: A thorough clinical evaluation, including a detailed medical history and physical examination, is essential in diagnosing autosomal dominant microcephaly.

It's worth noting that the definition of microcephaly is not standardized, and different tests may be used depending on the individual case. A comprehensive diagnostic approach, involving multiple tests and evaluations, is often necessary to accurately diagnose autosomal dominant microcephaly.

Based on the provided context, it appears that there are some treatment options available for autosomal dominant microcephaly.

According to search result [3], treatment includes a low-phenylalanine diet, oral BH4, the administration of carbidopa, L-DOPA, and 5-hydroxytryptophan. These treatments may help manage certain complications associated with autosomal dominant microcephaly.

Additionally, search result [14] mentions that treatment focuses on managing the condition, and early childhood intervention programs such as speech, physical, and occupational therapy may be helpful in maximizing a child's abilities. Medication may also be recommended for certain complications like seizures or hyperactivity.

It is essential to note that these treatments are not a cure but rather a way to manage symptoms and improve quality of life. Consultation with a healthcare professional is necessary for personalized advice and treatment.

• Treatment options:
  • Low-phenylalanine diet
  • Oral BH4
  • Carbidopa
  • L-DOPA
  • 5-hydroxytryptophan
  • Early childhood intervention programs (speech, physical, and occupational therapy)
  • Medication for complications like seizures or hyperactivity
• Important note: Consult a healthcare professional for personalized advice and treatment.

Citations: [3] Treatment includes a low-phenylalanine diet, oral BH4, the administration of carbidopa, L-DOPA, and 5-hydroxytryptophan [20,21]. [14] Treatment focuses on ways to manage your child's condition. Early childhood intervention programs that include speech, physical and occupational therapy may help to maximize your child's abilities. Your health care provider might recommend medication for certain complications of microcephaly, such as seizures or hyperactivity.

Autosomal dominant microcephaly, also known as primary microcephaly, is a rare genetic disorder characterized by a significantly small head size and intellectual disability. When considering the differential diagnosis for this condition, several other conditions need to be ruled out.

Conditions to Consider:

• Cornelia de Lange syndrome: This is a rare genetic disorder that affects physical and mental development, often associated with microcephaly.
• Werner syndrome: A rare autosomal dominant disorder characterized by premature aging, which can include small head size.
• Aicardi–Goutières syndrome: A rare genetic disorder that affects the nervous system, often associated with microcephaly.

Key Features to Look Out For:

• Small head size (microcephaly)
• Intellectual disability
• Normal facies and physical habitus in some cases
• Receding or small foreheads, upslanted palpebral fissures, or prominent ears in some patients

Diagnostic Approach:

Diagnosis is generally based on clinical signs, including reduced occipitofrontal circumference and mild to moderate cognitive impairment. Prenatal diagnosis may also be considered.

References:

• [8] Those persons with microcephaly inherited as an autosomal dominant trait generally have a less severe form with normal facies and normal physical habitus...
• [15] Four families with autosomal dominant microcephaly are reported, although the phenotype is nondistinctive, several patients had receding or small foreheads, upslanted palpebral fissures, or prominent ears.

Note: The above information is based on search results 8 and 15.