- Meningocele (HP:0002435): Protrusion of the meninges through a defect of the skull or vertebral column. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:268810)
- Neural tube defect (HP:0045005): A neural tube defect arises when the neural tube, the embryonic precursor of the brain and spinal cord, fails to close during neurulation. The cranial region (anencephaly) or the low spine (open spina bifida; myelomeningocele) are most commonly affected although, in the severe NTD craniorachischisis, almost the entire neural tube remains open, from midbrain to low spine. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:268810)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:268810)
- Hydrocephalus (HP:0000238): Hydrocephalus is an active distension of the ventricular system of the brain resulting from inadequate passage of CSF from its point of production within the cerebral ventricles to its point of absorption into the systemic circulation. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Enuresis (HP:0000805): Lack of the ability to control the urinary bladder leading to involuntary urination at an age where control of the bladder should already be possible. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Hypertonia (HP:0001276): A condition in which there is increased muscle tone so that arms or legs, for example, are stiff and difficult to move. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Gait disturbance (HP:0001288): The term gait disturbance can refer to any disruption of the ability to walk. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Tethered cord (HP:0002144): During normal embryological development, the spinal cord first occupies the entire length of the vertebral column but goes on to assume a position at the level of L1 due to differential growth of the conus medullaris and the vertebral column. The filum terminale is a slender, threadlike structure that remains after the normal regression of the distal embryonic spinal cord and attaches the spinal cord to the coccyx. A tethered cord results if there is a thickened rope-like filum terminale which anchors the cord at the level of L2 or below, potentially causing neurologic signs owing to abnormal tension on the spinal cord. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Chiari malformation (HP:0002308): Chiari malformation consists of a downward displacement of the cerebellar tonsils and the medulla through the foramen magnum, sometimes causing hydrocephalus as a result of obstruction of CSF outflow. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Hypokinesia (HP:0002375): Abnormally diminished motor activity. In contrast to paralysis, hypokinesia is not characterized by a lack of motor strength, but rather by a poverty of movement. The typical habitual movements (e.g., folding the arms, crossing the legs) are reduced in frequency. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Lower limb hyperreflexia (HP:0002395): Increased intensity of the a reflex in the leg. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Occipital meningocele (HP:0002436): A herniation of meninges through a congenital bone defect in the skull in the occipital region. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Bowel incontinence (HP:0002607): Involuntary fecal soiling in adults and children who have usually already been toilet trained. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Absent Achilles reflex (HP:0003438): Absence of the Achilles reflex (also known as the ankle jerk reflex), which can normally be elicited by tapping the tendon is tapped while the foot is dorsiflexed. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Limitation of neck motion (HP:0005986). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Upper limb spasticity (HP:0006986). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Thoracic hemivertebrae (HP:0008467): Absence of one half of the vertebral body in the thoracic spine. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Paraplegia (HP:0010550): Severe or complete weakness of both lower extremities with sparing of the upper extremities. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Lipomyelomeningocele (HP:0025480): A type of spinal dysraphism presenting as a subcutaneous fatty mass, that is, a spinal defect associated with lipomatous tissue, and covered by skin. The most usual location for lipomyelomeningocele is at the gluteal cleft. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Increased head circumference (HP:0040194): An abnormally increased head circumference in a growing child. Head circumference is measured with a nonelastic tape and comprises the distance from above the eyebrows and ears and around the back of the head. The measured HC is then plotted on an appropriate growth chart. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
- Hydromyelia (HP:0100565): Dilation of central canal from incomplete fusion of the posterior columns or persistence of the primitive large canal of the embryo. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:268810)
These phenotypes are associated with the disease Isolated posterior meningocele (ORPHA:268810).