Diagnosis of megalencephaly has changed over the years, however, with the development of more advanced equipment, physicians have been able to confirm the disorder with better accuracy. Usually, a physical exam is first performed when characteristics of megalencephaly have appeared. This typically occurs at birth or during early child development. A physician will then take head measurements in order to determine the circumference. This is known as the head circumference. Then a family background will be recorded in order to determine if there has been a history of megalencephaly in the family.

A neurological exam will then be performed using the technology of an MRI machine in order to confirm the diagnosis of megalencephaly. These imaging tests give detailed information regarding brain size, volume asymmetry and other irregular developments linked with MCAP, MPPH and hemimegalencephaly.

There is also a strong correlation of epilepsy and megalencephaly and this can aid doctors in their diagnosis.

If a diagnosis of megalencephaly is confirmed, the child is referred to a specialist who focuses on managing the symptoms and improving lifestyle. Since megalencephaly is usually presented with autism, the goal of treatment is to improve deficiencies associated with autistic causes. Additionally, since each patient has unique symptoms, there is no one specific treatment method and therefore is heavily reliant on symptoms associated with an individual.

Since there are very few treatment methods focused on managing megalencephaly, future research is targeted at inhibiting mutation of the pathway. However, this next step could be met with several complications as understanding the underlying mechanism of the mutation is a difficult task. The genetic coding that initiates a single mutation is sporadic and patterns are hard to detect in many cases.

Even thought very little research has been done to create inhibitors of the PI3K-AKT pathway, several pharmaceutical companies have begun to focus their interests in designing a prevention method for this purpose.

Molecular (DNA) testing for PAX6 gene mutations (by sequencing of the entire coding region and deletion/duplication analysis) is available for isolated aniridia and the Gillespie syndrome. For the WAGR syndrome, high-resolution cytogenetic analysis and fluorescence in situ hybridization (FISH) can be utilized to identify deletions within chromosome band 11p13, where both the PAX6 and WT1 genes are located.

There is no consensus on what degree of angulation justifies a diagnosis, an incline between 15° and 30° is typical. A similar-sounding term, camptodactyly, is a fixed flexion deformity of a digit.

Prevalence is estimated to be 0.005%. The age of onset has been found to be under 15 years in 40% of cases while it is between 10 and 14 years in one third of the cases. Females outnumber males, 4 to 1. Only 3% have attacks after age 52.

Hemihypertrophy, now more commonly referred to as hemihyperplasia in the medical literature, is a condition in which one side of the body or a part of one side of the body is larger than the other to an extent considered greater than the normal variation. As it is difficult to establish a set clinical criteria for diagnosis of hemihyperplasia, the dictum is often used that the clinician should be able to see the asymmetry "from the end of the bed".

Hemihyperplasia is a congenital overgrowth disorder and the asymmetry can range from mild to severe. It is important to establish a diagnosis because hemihyperplasia is associated with an increased risk for embryonal tumors, mainly Wilms tumor and hepatoblastoma. Due to the heightened tumor risk, there is a tumor screening protocol that is recommended for all children with isolated hemihyperplasia and Beckwith-Wiedemann Syndrome. Some of the other syndromes associated with hemihyperplasia may also follow this tumor surveillance protocol. The recommended tumor surveillance protocol is:

1. Any child with suspected isolated hemihyperplasia should be referred to a clinical geneticist for evaluation.

2. Abdominal ultrasound every 3 months until 7 years

3. Serum alpha fetoprotein measurement every 3 months until 4 years

4. Daily caretaker abdominal examination at the discretion of the provider/parent

In some cases, children with hemihyperplasia may have different leg lengths. There are two main surgical options for the treatment of uneven leg lengths- shortening and lengthening. Epiphysiodesis, which involves removing part of the growth plate of the longer leg, allowing the shorter leg to "catch up", may be performed on patients still able to grow. Bone resection is performed on patients who have no growth left and involves removing part of the bone. Leg lengthening procedures are more painful, involving the insertion of pins to be turned, moving parts of the bone apart (Ilizarov's Method). This process is reserved mainly for patients with a discrepancy greater than 4 cm, although some leg lengthening procedures are now done cosmetically. Non-surgical options include attachment of a lift to the shoe, allowing the patient to walk normally.

Children with hemihypertrophy may also develop scoliosis, a curvature of the spine.

Hemifacial hyperplasia is believed to be a minor form of hemihypertrophy.

Differential diagnoses can be:

- Todd's paresis

- Stroke

- Systemic lupus erythematosus

- Metabolic disorders

- Inherited disorders such as mitochondrial myopathy

Management entails careful examination and monitoring for malignant degenerations. Surgical interventions can correct or minimize deformities.

Benign hereditary chorea (BHC), also known as benign familial chorea, is a rare autosomal dominant neurogenetic syndrome. It typically presents in childhood with isolated chorea. Unlike other neurogenetic causes of chorea such as Huntington's disease, BHC is not progressive, and not associated with cognitive decline or psychiatric problems in the vast majority of cases.

BHC is caused by a single-nucleotide insertion mutation in "TITF1", which encodes thyroid transcription factor 1 (TTF-1). This gene is also known as NK2 homeobox 1 (NKX2-1)

In some cases, additional developmental abnormalities of lung and thyroid tissue are found in BHC, leading to the suggested alternative name "brain-lung-thyroid syndrome".

In Ollier disease isolated enchondromas are present without the presence of hemangiomas.

Due to a developmental arrest there is an abnormal alignment of the joint surfaces at either interphalangeal joint causing angulation in the plane of the palm. The finger may be slightly bent or have a very prominent bend.

Aniridia may be broadly divided into hereditary and sporadic forms. Hereditary aniridia is usually transmitted in an autosomal dominant manner (each offspring has a 50% chance of being affected), although rare autosomal recessive forms (such as Gillespie syndrome) have also been reported. Sporadic aniridia mutations may affect the WT1 region adjacent to the AN2 aniridia region, causing a kidney cancer called nephroblastoma (Wilms tumor). These patients often also have genitourinary abnormalities and intellectual disability (WAGR syndrome).

Several different mutations may affect the PAX6 gene. Some mutations appear to inhibit gene function more than others, with subsequent variability in the severity of the disease. Thus, some aniridic individuals are only missing a relatively small amount of iris, do not have foveal hypoplasia, and retain relatively normal vision. Presumably, the genetic defect in these individuals causes less "heterozygous insufficiency," meaning they retain enough gene function to yield a milder phenotype.

- AN

- Aniridia and absent patella

- Aniridia, microcornea, and spontaneously reabsorbed cataract

- Aniridia, cerebellar ataxia, and mental deficiency (Gillespie syndrome)

Hypoglossia is a short, incompletely developed tongue. It can occur either as an isolated malformation or in association with other deformities, particularly limb defects in a syndrome known as "oromandibular limb hypogenesis syndrome".

Adermatoglyphia is an extremely rare genetic disorder which causes a person to have no fingerprints. There are only four known extended families worldwide which are affected by this condition.

In 2011, the description of a case of a person from Switzerland lacking fingerprints as an isolated finding was published. The phenotype was mapped to chromosome 4q22. In the splice-site of a 3' exon of the gene for SMARCAD1-helicase, a point mutation was detected. It results in a shortened form of the skin-specific protein. The heterozygous mode of mutation suggests an autosomal dominant mode of inheritance.

Other conditions can cause a lack of fingerprints, but unlike them, adermatoglyphia has no other side effects. Mutations in helicases are involved in other rare genetic diseases, for instance Werner syndrome.

Currently there is no single diagnosis test for MS that is 100% sensitive and specific. To have such a thing would require a standardised definition of the disease, which currently does not exist. The most commonly used definition, based in the McDonald criteria, focuses in the presence and distribution of the lesions, not in the underlying condition that produces them. Therefore, even twins with the same underlying condition can be classified different

A Posterior Circulation Infarct (POCI) is a type of cerebral infarction affecting the posterior circulation supplying one side of the brain.

Posterior Circulation Stroke Syndrome (POCS) refers to the symptoms of a patient who clinically appears to have had a posterior circulation infarct, but who has not yet had any diagnostic imaging (e.g. CT Scan) to confirm the diagnosis.

It can cause the following symptoms:

- Cranial nerve palsy AND contralateral motor/sensory defect

- motor or sensory defect

- Eye movement problems (e.g.nystagmus)

- Cerebellar dysfunction

- Isolated homonymous hemianopia

It has also been associated with deafness.

Differential diagnosis is rarely difficult in adults. Onset is typically sudden with symptoms of horizontal diplopia. Limitations of eye movements are confined to abduction of the affected eye (or abduction of both eyes if bilateral) and the size of the resulting convergent squint or esotropia is always larger on distance fixation - where the lateral rectii are more active - than on near fixation - where the medial rectii are dominant. Abduction limitations which mimic VIth nerve palsy may result secondary to surgery, to trauma or as a result of other conditions such as myasthenia gravis or thyroid eye disease.

In children, differential diagnosis is more difficult because of the problems inherent in getting infants to cooperate with a full eye movement investigation. Possible alternative diagnosis for an abduction deficit would include:

1. Mobius syndrome - a rare congenital disorder in which both VIth and VIIth nerves are bilaterally affected giving rise to a typically 'expressionless' face.

2. Duane's syndrome - A condition in which both abduction and adduction are affected arising as a result of partial innervation of the lateral rectus by branches from the IIIrd oculomotor cranial nerve.

3. Cross fixation which develops in the presence of infantile esotropia or nystagmus blockage syndrome and results in habitual weakness of lateral rectii.

4. Iatrogenic injury. Abducens nerve palsy is also known to occur with halo orthosis placement.The resultant palsy is identified through loss of lateral gaze after application of the orthosis and is the most common cranial nerve injury associated with this device.

The first aims of management should be to identify and treat the cause of the condition, where this is possible, and to relieve the patient's symptoms, where present. In children, who rarely appreciate diplopia, the aim will be to maintain binocular vision and, thus, promote proper visual development.

Thereafter, a period of observation of around 9 to 12 months is appropriate before any further intervention, as some palsies will recover without the need for surgery.

Also inside standard MS different clinical courses can be separated.

Isolated congenital asplenia (ICAS) is a rare disease in humans that can cause life-threatening bacterial infections in children due to primary immunodeficiency. The infections can include pneumococal sepsis and meningitis.

ICAS is a ribosomopathy, due to autosomal dominant mutation of the "RPSA" gene on chromosome 3p21. Unlike heterotaxy syndrome, the absent spleen is not associated with other structural developmental defects.

The 1996 definition of the clinical courses of MS (phenotypes) was updated on 2013 by an international panel (International Advisory Committee on Clinical Trials).

While the main classification in 1996 was the recovery from the attacks (this clinical feature separates RR from progressive), in the updated revision the main classification is the activity.

MS courses in the new revision are divided into active and non-active, and CIS, when is active on MRI, becomes a kind of RRMS (this, of course, must be retrospectively diagnosed after the CDMS conversion)

Some reviews describe CIS as "the prodromal stage of MS".

In the above brachydactyly syndromes, short digits are the most prominent of the anomalies, but in many other syndromes (Down syndrome, Rubinstein-Taybi syndrome, etc.), brachydactyly is a minor feature compared to the other anomalies or problems comprising the syndrome.

A clinically isolated syndrome (CIS) is a clinical situation of an individual's first neurological episode, caused by inflammation or demyelination of nerve tissue. An episode may be monofocal, in which symptoms present at a single site in the central nervous system, or multifocal, in which multiple sites exhibit symptoms. CIS with enough paraclinical evidence can be considered as a clinical stage of Multiple Sclerosis (MS). It can also be retrospectively diagnosed as a kind of MS when more evidence is available.

Brain lesions associated with a clinically isolated syndrome may be indicative of several neurological diseases, like multiple sclerosis (MS) or Neuromyelitis optica. In order for such a diagnosis, multiple sites in the central nervous system must present lesions, typically over multiple episodes, and for which no other diagnosis is likely. A clinically definitive diagnosis of MS is made once an MRI detects lesions in the brain, consistent with those typical of MS. Other diagnostics include cerebrospinal fluid analysis and evoked response testing.

Currently it is considered that the best predictor of future development of clinical multiple sclerosis is the number of T2 lesions visualized by magnetic resonance imaging during the CIS. It is normal to evaluate diagnostic criteria against the "time to conversion to definite".

In 2001, the International Panel on the Diagnosis of Multiple Sclerosis issued the McDonald criteria, a revision of the previous diagnostic procedures to detect MS, known as the Poser criteria. "While maintaining the basic requirements of dissemination in time and space, the McDonald criteria provided specific guidelines for using findings on MRI and cerebrospinal fluid analysis to provide evidence of the second attack in those individuals who have had a single demyelinating episode and thereby confirm the diagnosis more quickly." Further revisions were issued in 2005.

Hereditary motor and sensory neuropathy with proximal dominance (HMSN-P) is an autosomal dominant neurodegenerative disorder that is defined by extensive involuntary and spontaneous muscle contractions, asthenia, and atrophy with distal sensory involvement following. The disease starts presenting typically in the 40s and is succeeded by a slow and continuous onslaught. Muscle spasms and muscle contractions large in number are noted, especially in the earliest stages. The presentation of HMSN-P is quite similar to amyotrophic lateral sclerosis and has common neuropathological findings. Sensory loss happens as the disease progresses, but the amount of sensation lost varies from case to case. There have been other symptoms of HMSN-P reported such as urinary disturbances and a dry cough.

Two large families in Japan have been identified with the disease locus to chromosome 3q. From descendants of Japan, HMSN-P was brought to Brazil, from there it is a pretty isolated disease. Through clinical studies, researchers identified that TFG mutations on chromosome 3q13.2 causes HMSN-P. "The presence of TFG/ubiquitin- and/or TDP-43-immunopositive cytoplasmic inclusions in motor neurons and cytosolic aggregation composed of TDP-43 in cultured cells expressing mutant TFG indicate a novel pathway of motor neuron death"

Henri Gougerot and Alexandre Carteaud originally described the condition in 1927. The cause remains unknown, but the observation that the condition may clear with Minocycline turned attention to an infectious agent. "Actinomycete Dietzia" strain X was isolated from one individual. Other antibiotics found useful include azithromycin, fusidic acid, clarithromycin, erythromycin, tetracycline and cefdinir.