Spasticity is also known to cause difficulty in performing activities of daily living such as bathing and showering, dressing, and self-feeding.Despite HSAS frequently being considered an isolated disorder of the central nervous system, its genetic basis also causes musculoskeletal defects that result in more than half of males with HSAS displaying thumbs that are adducted (clasped, or brought inwards towards the palm). Specifically, this abnormal presentation of the hand is due to congenital malformations in the extensor pollicis brevis and/or extensor pollicis longus muscle of forearm. MASA syndrome
MASA syndrome is named after its four principle features: mental retardation, adducted thumbs (clasped, or brought inwards towards the palm), shuffling gait, and aphasia (a language disability affecting the comprehension and production of speech as well as reading and writing abilities). Diagnosis
A healthcare provider, usually a medical geneticist (a physician with special training in diagnosing and managing genetic disorders) can provide a clinical diagnosis of L1 syndrome by examining a patient and ordering certain imaging studies, however the presence of L1 syndrome can only be confirmed when a molecular diagnosis has been made through genetic testing.Often, the diagnostic odyssey for a person with L1 syndrome begins prenatally (before they are born) when prenatal ultrasounds reveal non-specific brain abnormalities, ventriculomegaly, or a non-existent or underdeveloped corpus callosum. Fetuses with X-linked hydrocephalus with stenosis of the aqueduct of Sylvius (HSAS) will typically have hydrocephalus severe enough to be discovered upon routine fetal ultrasound as early as 18–20 weeks gestation.
After birth, in the presence of suggestive features (such as macrocephaly), hydrocephalus can be confirmed with noninvasive imaging including head magnetic resonance imaging, computed tomography, or ultrasound showing ventriculomegaly, or direct measurement of intracranial pressure through invasive techniques such as lumbar puncture. Further, the spasticity found in patients with HSAS can be easily demonstrated by examining the deep tendon reflexes and the extensor plantar reflex (which will both be abnormally brisk and strong due to damage to the cortex and internal capsule of the brain). There are various types of genetic testing that can be used to confirm an L1 syndrome diagnosis in a patient. After birth, genetic tests carry a low-risk of physical complications and are minimally-painful: for the patient, the process requires a small amount of blood being drawn from the arm using a needle. However, prenatal genetic testing carries significant risks for both the fetus and mother due to the need to remove genetic material from the fetus while it is still in utero. In order to conduct prenatal genetic testing, the mother and fetus must undergo either amniocentesis (the surgical puncturing of the amniotic sac, which holds the fetus in the womb) or, less frequently, chorionic villus sampling.