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Galloway-Mowat Syndrome

The information in NORD’s Rare Disease Database is for educational purposes only. It should never be used for diagnostic or treatment purposes. If you have questions regarding a medical condition, always seek the advice of your physician or other qualified health professional. NORD’s reports provide a brief overview of rare diseases. For more specific information, we encourage you to contact your personal physician or the agencies listed as “Resources” on this report.

Copyright 1996, 2002

Synonyms of Galloway-Mowat Syndrome

Disorder Subdivisions

General Discussion

Galloway-Mowat Syndrome, which is also known as Microcephaly-Hiatal Hernia-Nephrotic Syndrome, is an extremely rare genetic disorder that is characterized by a variety of physical and developmental abnormalities. Physical features may include an unusually small head (microcephaly) and additional abnormalities of the head and facial (craniofacial) area; damage to clusters of capillaries in the kidneys (focal glomerulosclerosis and/or diffuse mesangial sclerosis), resulting in abnormal kidney function (Nephrotic Syndrome); and, in many cases, protrusion of part of the stomach through an abnormal opening (esophageal hiatus) in the diaphragm (hiatal hernia). Additional physical abnormalities are often present. These may include various malformations of the brain, seizures, diminished muscle tone throughout the body (generalized hypotonia), and/or increased reflex reactions (hyperreflexia). Infants and children with Galloway-Mowat Syndrome may also exhibit developmental abnormalities including an inability to perform certain movement (motor) skills normal for their age and a profound delay in the attainment of skills requiring the coordination of muscular and mental activity (psychomotor retardation). Mental retardation may also be present. Galloway-Mowat Syndrome is inherited as an autosomal recessive trait.

Symptoms

Galloway-Mowat Syndrome, which is also known as Microcephaly-Hiatal Hernia-Nephrotic Syndrome, is an extremely rare genetic disorder that is characterized by a variety of physical and developmental abnormalities. Physical features may include malformations of the head and facial (craniofacial) area, such as an unusually small head (microcephaly) that appears flat at the top (vertex) and back (occiput); an abnormally high, narrow forehead; and/or widely spaced eyes (ocular hypertelorism). Some affected infants may also have unusually small jaw bones (micrognathia); a highly arched roof of the mouth (palate); and/or large, low-set ears.

In many infants with Galloway-Mowat Syndrome, part of the stomach may protrude through an abnormal opening (esophageal hiatus) where the esophagus passes through the diaphragm (hiatal hernia). As a result, the muscle that joins the esophagus and the stomach (esophagogastric junction) may not function appropriately, and there may be low pressure or inappropriate relaxation of the band of muscle fibers that closes the opening of the esophagus (lower esophageal sphincter). This allows the stomach's acidic contents to flow back into the esophagus (gastroesophageal reflux). (The esophagus is the muscular passageway that brings food from the throat to the stomach.) Such gastroesophageal reflux may cause affected infants to spit up and/or vomit repeatedly; in some cases, vomiting may be particularly forceful (projectile vomiting). Affected infants may fail to thrive due to the resulting loss of necessary calories and nutrients. Gastroesophageal reflux may also cause inflammation of the esophagus (esophagitis); choking; closure of the larynx due to sudden, violent laryngeal contractions (larygospasm); an inflammatory condition of the lungs caused by the entrance of food particles into the respiratory passages (aspiration pneumonia); and/or additional respiratory complications. (For more information on Gastroesophageal Reflux, see the Related Disorders section below.)

Infants with Galloway-Mowat Syndrome may also have several kidney (renal) abnormalities. The kidneys may be unusually large (nephromegaly); have an increased number of cells (hypercellularity); and/or contain several small cysts (microcystic dysplasia). In addition, clusters of capillaries (renal glomeruli), which normally filter the blood that passes through the kidneys (glomeruli filtration), may be replaced by scar tissue (focal glomerulosclerosis). In some cases, the thin membrane supporting the loops of capillaries that make up the renal glomeruli may also be replaced by fibrous, hardened scar tissue (diffuse mesangial sclerosis).

The resulting loss of the renal glomeruli's filtering ability causes the kidneys to function abnormally, and the affected individual exhibits a variety of symptoms (Nephrotic Syndrome) as a result. For example, the affected infant may excrete abnormally high levels of protein in the urine (proteinuria), specifically the protein albumin (albuminuria); have unusually low levels of albumin remaining in the blood (hypoalbuminemia); and exhibit anemia, weakness, an accumulation of fluid in the abdominal cavity (ascites), and/or an abnormal accumulation of fluid between layers of tissue under the skin (edema), particularly around the eye sockets (periorbital edema) and in the lowermost parts of the body, such as the ankles (dependent edema). The kidneys may eventually lose their ability to excrete waste products through the urine, to regulate the balance of salt and water in the body, and to perform their other vital functions (renal failure).

Infants with Galloway-Mowat Syndrome may also exhibit various malformations of the brain. Affected infants may have an abnormally small brain (microencephaly), and the internal layer of the cerebellum, which controls the coordination of movement, may be missing. The outer layer of the brain (cerebral cortex), which is responsible for conscious movement and thought, normally consists of several deep folds (gyri) and grooves (sulci). However, in infants with Galloway-Mowat Syndrome, the outer layer of the brain may have folds that are abnormally small (microgyria), or there may be a reduced number of folds that are larger than normal (pachygria). In other cases, the folds may be absent or incompletely formed (lissencephaly); as a result, the brain may have a smooth surface. (For more information on Lissencephaly, see the Related Disorders section below.)

Affected individuals may also exhibit absence or underdevelopment of myelin in various areas of the brain and spinal cord. Myelin, a substance made up of fatty (lipid) material and protein, enables effective transmission of nerve impulses through the brain and spinal cord by serving as an electrical insulator. In infants with Galloway-Mowat Syndrome, there may be an absence of myelin around nerve fibers in the cerebrum; there may also be underdevelopment of myelin (hypomyelination) in the spinal cord and/or brainstem.

Due to hypomyelination and/or the brain malformations described above, infants with Galloway-Mowat Syndrome may also exhibit neurological, neuromuscular, and/or developmental abnormalities. Neurological features may include a lack of response to stimuli in the environment and/or episodes of uncontrolled electrical disturbances in the brain that may cause convulsions, spasms, and/or other symptoms (seizures). (For more information on seizures, see Epilepsy in the Related Disorders section below.) Neuromuscular abnormalities may include diminished muscle tone throughout the body (generalized hypotonia); abnormally increased reflex reactions (hyperreflexia); poor ability to control movements of the head; and/or an inability to control hand, feet, and/or eye movements. Developmental abnormalities in affected infants and children may include an inability to perform certain movement (motor) skills normal for their age (e.g., sitting up, crawling, walking, and other developmental milestones) and a profound delay in the attainment of skills requiring the coordination of muscular and mental activity (psychomotor retardation). Mental retardation is usually present.

Causes

Galloway-Mowat Syndrome is an extremely rare genetic disorder that is inherited as an autosomal recessive trait. Human traits, including the classic genetic diseases, are the product of the interaction of two genes, one received from the father and one from the mother.

In recessive disorders, the condition does not appear unless a person inherits the same defective gene for the same trait from each parent. If one receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk of transmitting the disease to the children of a couple, both of whom are carriers for a recessive disorder, is twenty-five percent. Fifty percent of their children will be carriers, but healthy as described above. Twenty-five percent of their children will receive both normal genes, one from each parent, and will be genetically normal (for that particular trait). The risk is the same for each pregnancy.

Affected Populations

Galloway-Mowat Syndrome, which is also known as Microcephaly-Hiatal Hernia-Nephrotic Syndrome, is an extremely rare genetic disorder that affects males and females in equal numbers. Approximately 20 cases have been reported in the medical literature. Of the three main features associated with the disorder (microcephaly, hiatal hernia, and Nephrotic Syndrome), the unusual smallness of the infant's head (microcephaly) will be obvious at birth (congenital); symptoms occurring during the first weeks after birth may indicate the presence of a hiatal hernia; and the symptoms associated with Nephrotic Syndrome may become apparent within days, weeks, months, or, in some cases, two or three years after birth.

Related Disorders

Gastroesophageal Reflux is a very common condition in which the stomach's and/or part of the small intestine's (duodenal) acids or contents flow back into the esophagus, the muscular organ that brings food from the throat to the stomach. Symptoms may include vomiting, choking, and/or a sensation of warmth or burning in the esophagus. Affected individuals may also experience a sensation of deep pressure at the base of the neck, hoarseness, a need to clear the throat repeatedly, and/or wheezing while trying to sleep. Gastroesophageal Reflux is often caused by inappropriate relaxation or low pressure of the band of muscle fibers that closes the opening of the esophagus (lower esophageal sphincter); in some cases, it may be due to increased pressure in the abdominal area. This condition can occur at any age and may be due to a number of underlying disorders or conditions. (For more information on this disorder, choose "Gastroesophageal Reflux" as your search term in the Rare Disease Database.)

Lissencephaly is a rare abnormality in brain structure that may occur due to a variety of causes. It is a rare birth defect in which the folds of the brain are incompletely formed; as a result, the brain has a smooth surface instead of the normal folds and grooves. Affected individuals may exhibit additional abnormalities, such as a small head (microcephaly); an unusual facial appearance; seizures; and/or other brain, kidney (renal), heart (cardiac), and gastrointestinal malformations. Severe mental retardation may also be present. Lissencephaly may be due to a spontaneous (de novo) genetic change that occurs for unknown reasons (sporadic), be inherited as an autosomal recessive trait, or be due to and/or occur in association with various underlying disorders. (For more information on this disorder, choose "Lissencephaly" as your search term in the Rare Disease Database.)

Epilepsy is a group of disorders of the central nervous system characterized by repeated, uncontrolled electrical disturbances in the brain. Epileptic episodes, which are referred to as seizures, may be characterized by convulsions, spasms, sensory confusion, loss of consciousness, and/or disturbances in the nerves that control involuntary body functions (autonomic nervous system). The many different types of Epilepsy are classified according to the type of seizures that take place. Some types of Epilepsy occur as a symptom of other disorders, while others may be caused by head injuries. For example, in infants, the most common causes of recurrent epileptic seizures include developmental brain defects, metabolic disorders, a severe lack of oxygen (hypoxia), and/or brain injuries occurring before or after birth. (For more information on this group of disorders, choose "Epilepsy" as your search term in the Rare Disease Database.)

Standard Therapies

Diagnosis
Galloway-Mowat Syndrome, also known as Microcephaly-Hiatal Hernia-Nephrotic Syndrome, can be diagnosed after birth (postnatally) by a thorough clinical evaluation, characteristic physical findings, specialized laboratory tests, imaging techniques, and genetic testing. Of the three main symptoms associated with the disorder (microcephaly, hiatal hernia, and Nephrotic Syndrome), abnormalities of the head and facial (craniofacial) area, particularly the head's extremely small size (microcephaly) and unusual shape, are obvious at birth.

Recurrent spitting up and forceful vomiting during the first few weeks after birth may lead to suspicion of hiatal hernia. The presence of a hiatal hernia may be confirmed by x-ray (radiographic) examination, visualization with an optic instrument (endoscopy), and/or measurement of fluid pressure within the esophagus (esophageal manometry).

In affected infants, symptoms associated with Nephrotic Syndrome may become apparent within days, weeks, months, or in some cases, two or three years after birth. Urinary analysis may reveal small traces of blood (hematuria) and abnormally high levels of protein (proteinuria), specifically albumin (albuminuria), in the urine. Additional laboratory studies may reveal unusually low levels of albumin in an affected individual's blood (hypoalbuminemia). These findings, occurring in association with anemia and an abnormal accumulation of fluid that causes swelling (edema), may indicate a diagnosis of Nephrotic Syndrome. Microscopic examination (e.g., immunofluorescence and electron microscopy) of samples of kidney tissue (renal biopsy) may reveal renal abnormalities that may help to confirm a diagnosis of Nephrotic Syndrome, e.g., small cysts (microcystic dysplasia), an unusually large number of cells (hypercellularity), and/or abnormal deposits within and degeneration of portions of the kidneys due to the loss of the glomeruli's filtering ability (focal glomerulosclerosis and/or diffuse mesangial sclerosis).

Treatment
Treatment of Galloway-Mowat Syndrome is directed toward the specific symptoms that are apparent in each individual. Treatment may require the coordinated efforts of a team of specialists. Pediatricians, nephrologists, gastroenterologists, neurologists, surgeons, physical therapists, and/or others may need to work together to ensure a systematic, comprehensive approach to treatment.

Treatment for Nephrotic Syndrome in individuals with Galloway-Mowat Syndrome may include a low-sodium diet with low levels of protein. The edema associated with Nephrotic Syndrome may be treated with medications that promote the excretion of urine (diuretics). Drug therapy may also include antibiotics to help fight infection. In cases of renal failure, hemodialysis may be required to remove excess waste products from the blood.

For affected infants who also experience seizures, treatment may include therapy with anticonvulsant drugs to help prevent, reduce, or control seizures. Because individuals with Galloway-Mowat Syndrome may be receiving other drugs that may prohibit the use of certain anticonvulsant medications, each patient's case must be thoroughly coordinated by the physician team to determine the most appropriate therapies for each group of symptoms. (For more information on therapies for the treatment of Epilepsy, choose "Epilepsy" as your search term in the Rare Disease Database.)

Genetic counseling is advised for families of children with Galloway-Mowat Syndrome. Other treatment is symptomatic and supportive.

Investigational Therapies

Surgical removal of one or both kidneys (nephrectomy) has been used to treat individuals with early onset nephrotic syndrome. More research is necessary to determine the long-term safety and effectiveness of this potential treatment for individuals with conditions associated with early onset nephrotic syndrome such as Galloway-Mowat Syndrome.

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: prpl@cc.nih.gov

For information about clinical trials sponsored by private sources, contact:
www.centerwatch.com

Galloway-Mowat Syndrome Resources

Please note that some of these organizations may provide information concerning certain conditions (e.g., Microcephaly, Hiatal Hernia, or Nephrotic Syndrome) potentially associated with this disorder.

Organizations:

References

TEXTBOOKS
Birth Defects Encyclopedia: Mary Louise Buyse, Editor-In-Chief; Blackwell Scientific Publications, 1990. Pp. 865-66, 1142.

Harrison's Principles of Internal Medicine, 12nd Ed.: Jean D. Wilson et al., Editors; McGraw-Hill, Inc., 1991. P. 1177.

Diseases: Stanley Loeb et al., Editors; Springhouse Corporation, 1993. Pp. 817-19.

The Kidney, 4th Ed.: Barry M. Brenner and Floyd C. Rector, Jr., Editors; W. B. Saunders Company, 1991. Pp. 1233-38.

Principles of Neurology, 5th Ed.: Raymond D. Adams and Maurice Victor, Editors; McGraw-Hill, Inc., 1993. P. 1014.

JOURNAL ARTICLES
Srivastava T, et al. Podocyte proteins in Galloway-Mowat syndrome. Pediatr Nephrol. 2001;16:1022-29.

Lin CC, et al. Galloway-Mowat syndrome: a glomerular basement membrane disorder? Pediatr Nephrol. 2001;16:653-57.

De Vries BB, et al. Diagnostic dilemmas in four infants with nephrotic syndrome, microcephaly and severe developmental delay. Clin Dysmorphol. 2001;10:115-21.

Licht C, et al. Stepwise approach to the treatment of early onset nephrotic syndrome. Pediatr Nephrol. 2000;14:1077-82.

Kucharczuk K, et al. Additional findings in Galloway-Mowat syndrome. Pediatr Nephrol. 2000;14:406-09.

Futrakul P, et al. Improved renal perfusion prevents disease progression in focal segmental glomerulosclerosis. Nephron. 1995;69:351.

Neuhaus TJ, et al. Alternative treatment to corticosteroids in steroid sensitive idiopathic nephrotic syndrome. Arch Dis Child. 1994;71:522-26.

Artero ML, et al. Plasmapheresis reduces proteinuria and serum capacity to injure glomeruli in patients with recurrent focal glomerulosclerosis. Am J Kidney Dis. 1994;23:574-81.

Cohen AH, et al. Kidney in Galloway-Mowat syndrome: clinical spectrum with description of pathology. Kidney Int. 1994;45:1407-15.

Garty BZ, et al. Microcephaly and congenital nephrotic syndrome owing to diffuse mesangial sclerosis: an autosomal recessive syndrome. J Med Genet. 1994;31:121-25.

Cooperstone BG, et al. Galloway-Mowat syndrome of abnormal gyral patterns and glomerulopathy. Am J Med Genet. 1993;47:250-54.

Kozlowski PB, et al. Brain morphology in the Galloway syndrome. Clin Neuropathol. 1989;8:85-91.

Roos RA, et al. Congenital microcephaly, infantile spasms, psychomotor retardation, and nephrotic syndrome in two sibs. Eur J Pediatr. 1987;146:532-36.

Robain O, et al. Pachygyria and congenital nephrosis disorder of migration and neuronal orientation. Acta Neuropathol. 1983;60:137- 41.

Maher ER, et al. Cyclosporin in the treatment of steroid-responsive and steroid-resistant nephrotic syndrome in adults. Nephrol Dial Transplant. 1988;3:728-32.

Velosa JA, et al. Benefits and risks of nonsteroidal antiinflammatory drugs in steroid-resistant nephrotic syndrome. Am J Kidney Dis. 1986;8:345-50.

Futrakul P. A new therapeutic approach of nephrotic syndrome associated with focal segmental glomerulosclerosis. Int J Pediatr Nephrol. 1980;1:18-21.

Galloway WH, et al. Congenital microcephaly with hiatus hernia and nephrotic syndrome in two sibs. J Med Genet. 1968;5:319-21.

FROM THE INTERNET
McKusick VA, ed. Online Mendelian Inheritance in Man (OMIM). Baltimore. MD: The Johns Hopkins University; Entry No: 251300; Last Update:6/2/97.

Report last updated: 2008/03/16 00:00:00 GMT+0