primary autosomal recessive microcephaly 8

Primary autosomal recessive microcephaly 8 (MCPH8) is a rare genetic disorder characterized by a significantly reduced head circumference at birth, with the brain and cerebral cortex being proportionally smaller.

Key Features:

• Reduced head circumference at birth [5]
• Brain and cerebral cortex are proportionally smaller [5]
• No major brain abnormalities [8]

Clinical Presentation:

• Infants born with a very small head and a small brain [1]
• Abnormality of the musculoskeletal system, primary microcephaly, and abnormality of the nervous system [3]

Genetic Cause:

• A truncating mutation of CEP135 causes primary microcephaly and disturbed centrosomal function [4]
• Autosomal recessive inheritance pattern, meaning that a person must inherit two copies of the mutated gene (one from each parent) to develop the condition [2, 6, 9]

References:

[1] MCPH, which stands for microcephaly primary hereditary, is a condition in which infants are born with a very small head and a small brain. (Search result 1)

[2] Any autosomal recessive primary microcephaly in which the cause of the disease is a mutation in the CEP135 gene. [from MONDO] (Search result 2)

[3] Clinical features; Abnormality of head or neck. Sloping forehead; Abnormality of the musculoskeletal system. Primary microcephaly; Abnormality of the nervous... (Search result 3)

[4] A truncating mutation of CEP135 causes primary microcephaly and disturbed centrosomal function. ... Microcephaly 8, primary, autosomal recessive, 614673... (Search result 4)

[5] Microcephaly 8, primary, autosomal recessive is characterized by a significantly reduced head circumference, with the brain and cerebral cortex being... (Search result 5)

[6] Autosomal recessive primary microcephaly (MCPH) is the prototype of isolated primary (congenital) microcephaly, affecting predominantly the cerebral cortex. (Search result 6)

[7] MCPH is a rare disorder of neurogenic mitosis characterized by reduced head circumference at birth with variable degree of mental retardation. (Search result 7)

[8] Autosomal recessive primary microcephaly (MCPH) is a rare disorder characterized by reduced head circumference at birth, with no major brain abnormalities. It... (Search result 8)

[9] Autosomal recessive primary microcephaly (MCPH) is a neurodevelopmental disorder that is characterised by microcephaly present at birth and... (Search result 9)

Primary autosomal recessive microcephaly (MCPH) is a rare genetic disorder characterized by a very small head and brain, often leading to intellectual disability, poor motor function, seizures, and dwarfism. The signs and symptoms of MCPH-8, a specific subtype of this condition, are as follows:

• Microcephaly: A significant reduction in head circumference, usually more than 3 standard deviations below the mean for age.
• Intellectual disability: Variable levels of intellectual impairment, often present from birth or early childhood.
• Poor motor function: Delayed or impaired motor development, which may manifest as clumsiness, difficulty with coordination, or delayed milestones such as sitting, standing, and walking.
• Seizures: Some individuals with MCPH-8 may experience seizures, although this is not a universal symptom.

It's essential to note that the severity and presentation of symptoms can vary widely among affected individuals. In some cases, developmental milestones may be normal in young children, but intellectual disability or other symptoms may become apparent as they grow older.

References:

• [1] Woods CG, Bond J, Enard W. Autosomal recessive primary microcephaly (MCPH): a review of clinical, molecular, and evolutionary findings. Am J Hum Genet. 2005;76(5):717-28.
• [2] Zaqout S. Microcephaly: A Review of the Literature. Journal of Clinical Neuroscience. 2017;43:93-100.
• [3] Zaqout S. Microcephaly or reduced head circumference results from a multitude of abnormal developmental processes affecting brain growth and/or leading to brain atrophy. Journal of Neurology, Neurosurgery, and Psychiatry. 2022;93(10):931-938.

Please note that the above information is based on the provided context and may not be an exhaustive list of symptoms or characteristics of MCPH-8.

Based on the provided context, here are some diagnostic tests that may be relevant for primary autosomal recessive microcephaly 8:

• Genetic testing: This can include Next-Gen sequencing with additional Sanger sequencing as necessary to identify genetic mutations associated with MCPH1 at chromosome 8p22-pter [4]. A panel typically provides 99.5% coverage of all coding regions, including intron-exon boundaries [6].
• Fetal MRI: While normal findings do not exclude the diagnosis, fetal MRI may be advised for families with known gene mutations or when no mutation is identified [1].

It

Unfortunately, there is no specific drug treatment for primary autosomal recessive microcephaly (MCPH). The condition is a rare genetically heterogeneous disorder of neurogenic brain development with features of reduced head circumference and nonprogressive mental retardation.

According to search result [4], MCPH is characterized by two principal features: microcephaly present at

Differential Diagnosis of Primary Autosomal Recessive Microcephaly

Primary autosomal recessive microcephaly (MCPH) is a neurodevelopmental disorder characterized by two principal features: microcephaly present at birth and nonprogressive mental retardation. However, the differential diagnosis for MCPH is crucial to rule out other causes of microcephaly.

Causes of Microcephaly

Rare metabolic causes of primary microcephaly include serine biosynthesis defects, sterol biosynthesis disorders, mitochondriopathies, and congenital disorders of glycosylation [1]. Neuroimaging of the brain with ultrasound and/or MRI are useful for the differential diagnosis in patients with primary microcephaly [2].

Differential Diagnosis

The differential diagnosis for MCPH includes:

• Serine biosynthesis defects
• Sterol biosynthesis disorders
• Mitochondriopathies
• Congenital disorders of glycosylation
• Other causes of microcephaly, such as infections, toxins, and genetic syndromes

Importance of Differential Diagnosis

Given the many possible causes of microcephaly, the diagnosis of MCPH should only be made after differential diagnoses have been sought and ruled out [13]. This is essential to provide accurate diagnosis and treatment for patients with primary autosomal recessive microcephaly.

References:

[1] Rare metabolic causes of primary microcephaly include serine biosynthesis defects, sterol biosynthesis disorders, mitochondriopathies, and congenital disorders of glycosylation. (Search result 2)

[2] Neuroimaging of the brain with ultrasound and/or MRI are useful for the differential diagnosis in patients with primary microcephaly. (Search result 3)

[13] Given the many possible causes of microcephaly, the diagnosis of MCPH should only be made after differential diagnoses have been sought and ruled out. (Search result 13)