intellectual developmental disorder with short stature and behavioral abnormalities

Intellectual Developmental Disorder with Short Stature and Behavioral Abnormalities (IDDSSBA)

Intellectual developmental disorder with short stature and behavioral abnormalities is a rare, genetic disorder characterized by severe intellectual disability, short stature, acquired microcephaly, kyphoscoliosis or scoliosis, and behavioral disturbances such as hyperactivity, stereotypy, and aggressiveness [1][3].

Key Features:

• Severe intellectual disability with limited or absent speech and language
• Short stature, often below the 3rd percentile for age and gender
• Acquired microcephaly (small head size)
• Kyphoscoliosis or scoliosis (abnormal curvature of the spine)
• Behavioral disturbances:
  • Hyperactivity
  • Stereotypy (repetitive behaviors)
  • Aggressiveness
• Seizures are also a common feature [4]

Causes and Genetics:

IDDSSBA is an autosomal recessive disorder, meaning that it is inherited in an autosomal recessive pattern. This means that the individual must inherit two copies of the mutated gene (one from each parent) to express the condition [5].

The condition is caused by a homozygous mutation in the IQSEC1 gene on chromosome 3p25 [5].

References:

[1] Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms).

[3] A syndrome characterized by intellectual disability, global developmental delay, short stature, aphasia, and hypotonia that has_material_basis_in homozygous ...

[4] An autosomal recessive disorder characterized by intellectual disability, developmental delay with poor or absent speech, short stature, progressive ...

[5] A number sign (#) is used with this entry because of evidence that intellectual developmental disorder with short stature and behavioral abnormalities (IDDSSBA) is caused by homozygous mutation in the IQSEC1 gene (610166) on chromosome 3p25.

Intellectual Developmental Disorder with Short Stature and Behavioral Abnormalities

Individuals with intellectual developmental disorder (IDD) often exhibit a range of signs and symptoms that can vary in severity. When combined with short stature, the condition can manifest differently than when it occurs alone.

• Short stature: This is a common feature of IDD with short stature and behavioral abnormalities, where individuals may have a height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender-dependent norms) [1].
• Behavioral disturbances: These can include hyperactivity, stereotypy, and aggressiveness, which are often present in individuals with IDD and short stature [2]. Behavioral disturbances may also manifest as frequent temper tantrums and outbursts, aggression, anxiety, impulsiveness, and difficulty paying attention [3].
• Developmental delays: Individuals with IDD and short stature may experience delayed or slowed learning of any kind (such as in school or from real-life experiences), which can lead to difficulties with reasoning and logic [4].
• Microcephaly: Acquired microcephaly is a feature of some cases of IDD with short stature and behavioral abnormalities, where the head circumference is smaller than expected for age [5].
• Gait abnormalities: Some individuals may experience gait abnormalities, tremors, or seizures as part of their condition [6].

It's essential to note that each individual with IDD and short stature will exhibit a unique set of signs and symptoms. A comprehensive evaluation by a qualified healthcare professional is necessary for an accurate diagnosis and development of a personalized treatment plan.

References:

[1] Context result 1 [2] Context result 2 [3] Context result 6 [4] Context result 4 [5] Context result 7 [6] Context result 8

Recommended Diagnostic Approach

The recommended clinical genetics diagnostic approach for intellectual developmental disorder with short stature and behavioral abnormalities (IDDSSBA) involves a combination of medical history, physical examination, and laboratory tests.

• Initial Evaluation: The first step is to conduct an initial evaluation, which includes taking a detailed medical history, performing a thorough physical examination, and assessing the individual's developmental and adaptive functioning. This evaluation helps identify any potential underlying causes of IDDSSBA.
• Laboratory Testing: If the initial evaluation does not suggest a diagnosis, laboratory testing may be performed to rule out other conditions that could be causing the symptoms. Chromosomal microarray (CMA) is designated as a first-line test and replaces the standard karyotype and fluorescent in situ hybridization subtelomere tests for the diagnostic workup of IDDSSBA [3].
• Chromosomal Microarray: CMA has replaced karyotype analysis as the first laboratory test for developmental delay (DD), intellectual disability (ID), and autism spectrum disorders (ASDs) of unknown etiology. It is also now the first-line test for patients with multiple congenital anomalies (MCAs) [13].
• Genetic Testing: Genetic testing, including targeted gene panels and whole-exome sequencing, may be considered if CMA results are normal or inconclusive. The IQSEC1 gene has been identified as a cause of IDDSSBA, and genetic testing for this gene may be recommended in certain cases [15].

Diagnostic Tests

The following diagnostic tests may be used to diagnose IDDSSBA:

• Chromosomal microarray (CMA)
• Karyotype analysis
• Fluorescent in situ hybridization subtelomere tests
• Targeted gene panels
• Whole-exome sequencing

References

[3] Chromosome microarray is designated as a first-line test and replaces the standard karyotype and fluorescent in situ hybridization subtelomere tests for the diagnostic workup of IDDSSBA. [13] Chromosomal microarray (CMA) has replaced karyotype analysis as the first laboratory test for developmental delay (DD), intellectual disability (ID), and autism spectrum disorders (ASDs) of unknown etiology. [15] A number sign (#) is used with this entry because of evidence that intellectual developmental disorder with short stature and behavioral abnormalities (IDDSSBA) is caused by homozygous mutation in the IQSEC1 gene (610166) on chromosome 3p25.

Intellectual developmental disorders (IDDs) with short stature and behavioral abnormalities are complex conditions that require a comprehensive treatment approach. While there is no cure for IDDs, various medications can help manage associated symptoms such as hyperactivity, aggression, and anxiety.

Medications commonly used:

• Antipsychotics: These medications are often prescribed to manage symptoms of psychosis, agitation, and aggression in individuals with IDD. Examples include risperidone (Risperdal) and aripiprazole (Abilify).
• Mood stabilizers: Medications like lithium and valproate can help regulate mood swings and reduce the risk of seizures.
• Antidepressants: Selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine (Prozac) may be used to treat symptoms of depression, anxiety, or obsessive-compulsive disorder.

Important considerations:

• Dosage and administration: Medications should be prescribed in the lowest effective dose and administered according to a treatment plan developed by a qualified healthcare professional.
• Monitoring and follow-up: Regular monitoring of medication efficacy and potential side effects is crucial to ensure safe and effective treatment.
• Individualized approach: Treatment plans should take into account the unique needs, medical history, and lifestyle of each individual with IDD.

References:

• Deb, S. (2016). Psychopharmacology. In: N. N. Singh (Ed.), 'Handbook of Evidence-Based Practices in Intellectual and Developmental Disabilities, Evidence-Based Practices in Behavioral Health.' Springer International Publishing, Switzerland, Cham.
• Orphanet (2021) - Neuroleptic drugs for behavioral disturbances in intellectual disability.

Please consult with a healthcare professional for medical advice and treatment.

Intellectual developmental disorder with short stature and behavioral abnormalities can be challenging to diagnose, as it shares similar symptoms with other conditions. Here are some potential differential diagnoses to consider:

• Prader-Willi Syndrome (PWS): This genetic disorder is characterized by short stature, obesity, hypogonadism, and intellectual disability. Individuals with PWS often exhibit