Simpson-Golabi-Behmel syndrome type 2

Simpson-Golabi-Behmel Syndrome Type 2 (SGBS2)

SGBS2 is a rare and severe X-linked recessive disorder that affects males, characterized by severely impaired intellectual development, ciliary dyskinesia, and macrocephaly [1][3][5]. This condition is distinct from the classical form of Simpson-Golabi-Behmel syndrome (SGBS), which has a milder phenotype.

Key Features:

• Severely impaired intellectual development
• Ciliary dyskinesia (abnormalities in cilia function)
• Macrocephaly (larger-than-normal head size)
• Severe overgrowth and organomegaly (enlargement of organs)

Prognosis: Affected individuals with SGBS2 typically live only into infancy, making it an extremely rare and severe form of the syndrome [4][6].

Genetic Heterogeneity: The genetic basis of SGBS2 is not fully understood, but it is believed to be caused by mutations in an X-linked gene. This condition shows phenotypic similarities to other overgrowth syndromes, such as Beckwith-Wiedemann syndrome (BWS) [12].

References:

[1] Budny et al., 2006 - Summary of SGBS2 characteristics [3] Simpson-Golabi-Behmel syndrome type 2 (SGBS2) is an X-linked recessive disorder in which affected males have severely impaired intellectual development, ciliary dyskinesia, and macrocephaly. [5] Terespolsky et al., 1995 - Description of SGBS2 as a lethal and infrequent form [6] Disease Overview. Simpson-Golabi-Behmel syndrome (SGBS) type 2 is an extremely rare and severe, early-lethal form of SGBS... [12] Simpson-Golabi-Behmel syndrome is an X-linked condition characterized by pre- and postnatal overgrowth, coarse facies, congenital heart defects, and other congenital abnormalities.

Simpson-Golabi-Behmel syndrome type 2 (SGBS2) is a rare X-linked recessive disorder that affects males, characterized by severe intellectual disability. The signs and symptoms of SGBS2 include:

• Severe intellectual disability: Affected males have severely impaired intellectual development [9].
• Multiple congenital anomalies: SGBS2 is associated with multiple congenital abnormalities, including heart defects, malformed or abnormally large kidneys, an enlarged liver and spleen [1], [4].
• Overgrowth: Prenatal and postnatal overgrowth are characteristic features of SGBS2.
• Distinctive craniofacial features: Affected males may have distinctive craniofacial features, although the exact nature of these features is not specified in the available context.

It's worth noting that SGBS2 is an extremely rare and severe form of Simpson-Golabi-Behmel syndrome, with a high mortality rate. The exact prevalence and clinical presentation of SGBS2 are not well-documented in the provided context.

References: [1] Jul 1, 2017 — Simpson-Golabi-Behmel syndrome can also cause heart defects, malformed or abnormally large kidneys, an enlarged liver and spleen ( ... [4] Jul 1, 2017 — Simpson-Golabi-Behmel syndrome can also cause heart defects, malformed or abnormally large kidneys, an enlarged liver and spleen ( ... [9] Simpson-Golabi-Behmel syndrome type 2 (SGBS2) is an X-linked recessive disorder in which affected males have severely impaired intellectual development.

Simpson-Golabi-Behmel syndrome type 2 (SGBS2) is a rare and severe genetic disorder, and its diagnosis can be challenging. However, several diagnostic tests are available to aid in the identification of this condition.

Genetic Testing

Genetic testing plays a crucial role in diagnosing SGBS2. The following tests can help identify the underlying genetic cause:

• Array comparative genomic hybridization (aCGH): This test analyzes the genetic material for deletions or duplications, which are characteristic of SGBS2 [3].
• Genetic testing for GPC3 mutations: Mutations in the GPC3 gene are associated with SGBS2. Genetic testing can help identify these mutations and confirm the diagnosis [4].
• Array-based molecular karyotyping: This test can also be used to identify chromosomal abnormalities, which may contribute to the development of SGBS2 [1].

Clinical Evaluation

In addition to genetic testing, a thorough clinical evaluation is essential for diagnosing SGBS2. The following factors are considered:

• Family history: A family history of SGBS2 or other related disorders can increase the likelihood of diagnosis.
• Clinical findings: Physical examination and medical history can reveal characteristic features of SGBS2, such as overgrowth, intellectual disability, and multiple congenital anomalies [6].
• Pedigree analysis: Analyzing the family tree can help identify patterns of inheritance and confirm the diagnosis.

Other Diagnostic Tests

While not specific to SGBS2, other diagnostic tests may be used in conjunction with genetic testing and clinical evaluation:

• Whole exome sequencing: This test analyzes the entire genome for mutations that may contribute to the development of SGBS2 [1].
• Imaging studies: Imaging studies such as ultrasound or MRI may be used to evaluate fetal development or identify congenital anomalies.

It is essential to consult with a genetic counselor or a medical professional experienced in diagnosing rare genetic disorders to determine the best course of action for diagnosis and management of SGBS2.

Simpson-Golabi-Behmel syndrome (SGBS) type 2 is a rare overgrowth disorder that affects many parts of the body, primarily in males. According to available information, there are various treatment options for SGBS type 2.

• Multidisciplinary support: A comprehensive approach involving multiple specialists, such as pediatricians, surgeons, and cardiologists, is essential for managing the condition [7].
• Treatment of neonatal hypoglycemia: Hypoglycemia in newborns with SGBS type 2 requires prompt treatment to prevent complications [7].
• Propranolol therapy: Propranolol, a beta-blocker, may be used to manage cardiac abnormalities and prevent dilation of the ascending aorta [9].

It's worth noting that there is limited information available on specific drug treatments for SGBS type 2. However, various management strategies are employed to address associated symptoms and complications.

References: [7] - Management & treatment. General management. It includes treatment of neonatal hypoglycemia and multidisciplinary support of many pediatric specialists. [9] - Propranolol, which reduces the pounding of the ventricular ejection on the ascending aorta, is routinely used in patients who are beginning to have dilation of the ascending aorta.

Simpson-Golabi-Behmel syndrome type 2 (SGBS type 2) is a rare genetic disorder characterized by overgrowth and multiple congenital anomalies. When considering the differential diagnosis for SGBS type 2, several other conditions should be taken into account.

• Beckwith-Wiedemann syndrome: This condition is also an overgrowth syndrome, similar to SGBS type 2. It is characterized by excessive growth before birth, and affected individuals may have a range of physical abnormalities, including macrocephaly (large head size) [1].
• Fragile X syndrome: Another genetic disorder that can present with overgrowth and developmental delays, fragile X syndrome is caused by mutations in the FMR1 gene. It is often associated with intellectual disability and distinctive physical features [4][7].
• Perlman syndrome: This rare condition is characterized by prenatal and postnatal overgrowth, as well as various congenital anomalies. Like SGBS type 2, it can be associated with an increased risk of cancer [3][7].

It's essential to note that the differential diagnosis for SGBS type 2 may also include other conditions such as Weaver syndrome and Sotos syndrome, which are both characterized by overgrowth and intellectual disability [3][4]. However, a definitive diagnosis of SGBS type 2 can be made through genetic testing.

References: [1] Aug 7, 2020 — In SGBS type 1, one of the main features is overgrowth, which is when an individual is larger than expected. [3] by J Tenorio · 2014 · Cited by 98 — Other entities that should be considered in the general differential diagnosis of SGBS syndrome are: Weaver syndrome, Perlman syndrome ... [4] Nov 29, 2020 — Differential diagnosis. Differential diagnosis includes 1,5,7: Beckwith-Wiedemann syndrome · Fragile X syndrome · Perlman syndrome · Sotos ... [7] by J Tenorio · 2014 · Cited by 98 — Other entities that should be considered in the general differential diag- nosis of SGBS syndrome are: Weaver syndrome, Perlman syndrome; Fragile X syndrome; ...