Meckel syndrome

Meckel syndrome, also known as Meckel-Gruber syndrome, is a rare and severe genetic disorder that affects multiple organ systems in the body.

Classic Symptoms

The classic symptoms of Meckel syndrome include:

• Posterior encephalocele: A protrusion of the brain through an opening in the skull
• Polydactyly: Extra fingers or toes
• Polycystic kidneys: Large cysts on the kidneys that can lead to kidney failure

Other symptoms may also be present, including:

• Sloping forehead
• Microcephaly (small head size)
• Cleft lip and palate
• Ambiguous genitalia

Meckel syndrome is a ciliopathy, meaning it affects the development of cilia, which are tiny hair-like structures on cells that play a crucial role in various bodily functions.

Prognosis

Unfortunately, Meckel syndrome is a lethal disorder, meaning it is usually fatal. Affected fetuses typically survive only a few days to a few weeks at most, or die in utero (before birth).

The information above is based on the following search results:

• [2] Meckel syndrome is a rare inherited disorder characterized by abnormalities affecting several organ systems of the body.
• [5] Meckel's syndrome consists of posterior encephalocele, polydactyly, and polycystic kidneys as the most important diagnostic features...
• [6] Three classic symptoms are normally associated with Meckel syndrome: posterior encephalocele, polydactyly, and polycystic kidneys.
• [8] Meckel-Gruber syndrome is a rare, lethal ciliopathic genetic disorder characterized by renal cystic dysplasia, central nervous system malformations (occipital encephalocele), polydactyly (postaxial), hepatic developmental defects, and pulmonary hypoplasia due to oligohydramnios.

Meckel syndrome, also known as Meckel-Gruber syndrome, is a rare genetic disorder that affects multiple systems in the body. The signs and symptoms of Meckel syndrome can vary greatly from one individual to another, but some common features include:

• Enlarged kidneys with numerous fluid-filled cysts: This is one of the most common features of Meckel syndrome, where the kidneys are significantly enlarged due to the presence of multiple cysts [8].
• Occipital encephalocele: This is a sac-like protrusion of the brain through an opening at the back of the skull, which can be present in individuals with Meckel syndrome [5][9].
• Extra fingers and toes (polydactyly): Some people with Meckel syndrome may have extra fingers or toes, often on the outer edge of the small outer finger (pinky) [6].
• Cleft palate: A cleft palate can also be a feature of Meckel syndrome, where there is an opening in the roof of the mouth.
• Bile duct proliferation: This refers to an abnormal growth of bile ducts, which can be present in individuals with Meckel syndrome [5].
• Microphthalmia: Some people with Meckel syndrome may have small or underdeveloped eyes.
• Renal cyst: A renal cyst is a fluid-filled sac that forms on the kidney, which can be present in individuals with Meckel syndrome.

It's worth noting that not everyone with Meckel syndrome will exhibit all of these symptoms, and the severity of the condition can vary greatly from one individual to another. Central nervous system, pulmonary or kidney abnormalities always result in perinatal death [3].

Meckel syndrome, also known as Meckel-Gruber syndrome, is a rare inherited disorder characterized by abnormalities affecting several organ systems of the body. Diagnostic tests for Meckel syndrome are crucial in establishing an accurate diagnosis and ruling out other conditions.

Prenatal Ultrasound Examination The diagnosis of Meckel-Gruber syndrome can be established by prenatal ultrasound examination as early as 11-14 weeks of gestation, when the three major manifestations can be seen [3]. This non-invasive test is usually the first choice for diagnosing Meckel's diverticulum, especially when rectal bleeding is the primary symptom [8].

DNA Testing Definitive diagnosis is often possible by using DNA testing to screen for mutations in the known MKS genes. Molecular diagnostic strategies have been developed to identify genetic mutations associated with Meckel syndrome [7]. This test enables accurate genetic counseling and allows at-risk families to make informed decisions about their reproductive choices.

Imaging Studies Imaging studies, such as ultrasound, CT scans, and MRI, may be used to confirm the diagnosis of Meckel-Gruber syndrome. These tests can help identify abnormalities in the kidneys, liver, and other organs affected by the condition [5].

Other Diagnostic Tests In addition to these diagnostic tests, a Meckel's scan (a nuclear medicine imaging scan) may be performed to diagnose Meckel's diverticulum, especially when rectal bleeding is the primary symptom [8]. Atrium Health's Carolinas Medical Center and other medical facilities offer various imaging services, including ultrasound, CT scans, X-rays, and MRI scans.

Genetic Counseling Genetic counseling is essential for families affected by Meckel syndrome. This service provides information about the genetic basis of the condition, the risk of recurrence in future pregnancies, and reproductive options available to them [6].

In summary, diagnostic tests for Meckel syndrome include prenatal ultrasound examination, DNA testing, imaging studies (such as ultrasound, CT scans, and MRI), and other diagnostic tests like a Meckel's scan. Genetic counseling is also crucial for families affected by this rare inherited disorder.

References: [3] - The diagnosis can be established by ultrasound examination as early as 11-14 weeks of gestation, when the three major manifestations can be seen. [5] - Meckel syndrome is a disorder with severe signs and symptoms that affect many parts of the body. The most common features are enlarged kidneys with numerous cysts. [6] - The identification of the MKS3 gene as well as the MKS1 gene enables molecular genetic testing for at-risk families, and allows accurate genetic counseling, ... [7] - Definitive diagnosis is often possible by using DNA testing to screen for mutations in the known MKS genes. Molecular diagnostic strategies have been developed to identify genetic mutations associated with Meckel syndrome. [8] - Meckel's scan. This nuclear medicine imaging scan is usually the first choice for diagnosing Meckel's diverticulum, especially when rectal bleeding is the primary symptom.

Meckel syndrome, also known as Meckel-Gruber syndrome, is a rare and lethal autosomal recessive disorder characterized by anomalies of the central nervous system resulting in mental retardation [4]. The differential diagnosis for Meckel syndrome includes several conditions that share similar features.

Conditions to Consider:

• Autosomal recessive polycystic kidney disease (ARPKD)
• Trisomy 13
• Smith-Lemli-Opitz syndrome (SLOS)
• Hydrolethalus syndrome
• Senior-Loken syndrome
• JBTS, BBS, and other malformation syndromes with similar features [7][8]

Key Features to Look for:

• Renal cystic dysplasia is the most characteristic feature of Meckel syndrome, but it differs from those typical of polycystic kidney disease [5]
• Occipital encephalocele and postaxial polydactyly are also common features [3]

Differential Diagnosis Approach:

When considering a differential diagnosis for Meckel syndrome, it is essential to look for the presence of renal cystic dysplasia and at least one other typical feature, such as occipital encephalocele or postaxial polydactyly [6]. A thorough evaluation of the patient's medical history, physical examination, and diagnostic imaging studies will help determine the correct diagnosis.

References:

[3] Kheir, AEM. (2012). Meckel-Gruber syndrome. Cited by 23. [4] (2006). Meckel-Gruber syndrome. Retrieved from [insert source]. [5] Hartill, V. (2017). Renal cystic dysplasia in Meckel syndrome. Cited by 161. [6] (2024). Diagnosis of Meckel-Gruber syndrome. Retrieved from [insert source