hydrolethalus syndrome 2

Hydrolethalus syndrome 2 (HLS2) is an autosomal recessive embryonic lethal disorder characterized by hydrocephaly or anencephaly, postaxial polydactyly of the upper limbs, and pre- or postaxial polydactyly of the lower limbs. Duplication of the hallux is a common finding in individuals with HLS2.

This condition is considered a ciliopathy, which means that it is caused by a problem with the development of cilia, microscopic projections on cells that are important for sensory input and signaling output.

The symptoms of HLS2 can vary, but they often include:

• Hydrocephaly or anencephaly (fluid accumulation in the brain or absence of the upper part of the skull)
• Postaxial polydactyly of the upper limbs (extra fingers on the hands)
• Pre- or postaxial polydactyly of the lower limbs (extra toes on the feet)
• Duplication of the hallux (extra big toe)

HLS2 is a rare genetic disorder that can be diagnosed prenatally, and it is often associated with stillbirth.

References:

[1] Putoux et al. (2011) - HLS2 is considered a ciliopathy. [4] An embryonic lethal disorder characterized by hydrocephaly or anencephaly, postaxial polydactyly of the upper limbs, and pre- or postaxial polydactyly of the lower limbs. [14] Hydrolethalus syndrome is an autosomal recessive embryonic lethal disorder characterized by hydrocephaly or anencephaly, postaxial polydactyly of the upper limbs, and pre- or postaxial polydactyly of the lower limbs. Duplication of the hallux is a common finding. [15] Description. Hydrolethalus syndrome is an autosomal recessive embryonic lethal disorder characterized by hydrocephaly or anencephaly, postaxial polydactyly of the upper limbs, and pre- or postaxial polydactyly of the lower limbs.

Hydrolethalus syndrome 2 (HLS2) is a rare genetic disorder that affects fetal development, resulting in severe birth defects. The signs and symptoms of HLS2 are characterized by:

• Craniofacial dysmorphic features: This includes abnormalities in the shape and structure of the head, face, and skull.
• Central nervous system abnormalities: These can include hydrocephaly (fluid accumulation in the brain) or anencephaly (absence of a major part of the brain).
• Cardiac abnormalities: Heart defects are common in HLS2 patients.
• Respiratory tract abnormalities: Issues with the lungs and airways are also present.
• Limb abnormalities: Polydactyly (extra fingers or toes) is a common finding, particularly postaxial polydactyly of the upper limbs.

Additionally, duplication of the hallux (big toe) is a common feature in HLS2 patients. It's essential to note that these symptoms can vary in severity and may not be present in every individual with HLS2.

According to [12], HLS2 is considered a ciliopathy, which means it affects the development and function of cilia, microscopic projections on cells that play a crucial role in sensory input and signaling output. This understanding has significant implications for the diagnosis and management of HLS2.

It's worth noting that HLS2 is an autosomal recessive disorder, meaning that affected individuals inherit two copies of the mutated gene (one from each parent). As a result, there is a 25% recurrence risk after an affected pregnancy [14].

Hydrolethalus syndrome 2 (HLS2) is a rare genetic disorder that can be diagnosed through various diagnostic tests.

• Sequence analysis of select exons: This test involves analyzing specific exons of the KIF7 gene to identify any mutations that may cause HLS2. [1]
• Sequence analysis of the entire coding region: This test analyzes the entire coding region of the KIF7 gene to identify any mutations that may cause HLS2. [11]
• Deletion/duplication analysis: This test identifies any deletions or duplications in the KIF7 gene that may cause HLS2. [3]
• Targeted next-generation sequencing (NGS): This test involves analyzing specific genes, including the KIF7 gene, to identify any mutations that may cause HLS2. [7]

Additionally, genetic testing of the affected child can help verify the mutation and provide a diagnosis for HLS2. [15] Brain imaging, autopsy, and physical examination can also be used to diagnose HLS2 in newborns.

It's worth noting that prenatal diagnosis is possible through genetic testing of the affected child, which can help identify the mutation and provide a diagnosis for future pregnancies. [15]

References: [1], [3], [7], [11] - Context 3, 4, 5, 10 [15] - Context 15

Unfortunately, it appears that there is no effective drug treatment available for Hydrolethalus Syndrome 2 (HLS). According to the search results:

• There is no mention of any specific drugs or treatments in search result [1].
• Search result [9] mentions that "No treatment available for the underlying lethal disorder" (Fig. 1), which suggests that there is currently no effective medical intervention for HLS.
• The other search results provide information on the genetic and developmental aspects of HLS, but do not mention any potential drug treatments.

It's worth noting that Hydrolethalus Syndrome 2 is a rare and severe fetal malformation syndrome, and as such, it may be challenging to develop effective treatments. However, ongoing research and advances in medical science may lead to new discoveries and potential therapeutic options in the future.

References: * [9]

Differential Diagnosis of Hydrolethalus Syndrome 2 (HLS2)

Hydrolethalus syndrome 2 (HLS2) is a rare genetic disorder characterized by severe fetal malformations. When considering the differential diagnosis of HLS2, several other midline multiple malformation syndromes should be taken into account.

• Pallister-Hall Syndrome: This condition shares similarities with HLS2 in terms of its midline malformation features. However, it is typically associated with hypothalamic hamartomas and other distinct characteristics.
• Smith-Lemli-Opitz Syndrome: A severe genetic disorder that affects the development of multiple organs and systems, including the central nervous system, heart, and limbs. While it shares some similarities with HLS2, it is characterized by a specific metabolic defect.
• Pseudo-trisomy 13: A rare chromosomal disorder that can present with midline malformations similar to those seen in HLS2. However, it typically involves additional chromosomal abnormalities.
• Joubert Syndrome: A genetic disorder affecting the development of the brain and other organs, often presenting with midline malformation features.

These conditions should be considered in the differential diagnosis of HLS2, particularly when evaluating patients with similar midline malformation characteristics. Accurate diagnosis is crucial for providing appropriate management and support to affected individuals and their families.

References:

• [3] Differential diagnosis of HLS includes other midline multiple malformation syndromes like Pallister-Hall, pseudo-trisomy 13, oro-facio-digital type IV or VI, Joubert syndromes, as well as the severe form of Smith-Lemli-Opitz syndrome (see these terms).
• [4] Differential diagnosis: Other midline malformation syndromes including:Pallister-Hall, Smith-Lemli-Opitz, pseudo-trisomy 13, ...