Handbook of Genetic Counseling/Hypotonia - Developmental Delay

Hypotonia - Developmental Delay

Contracting

 * Introductions, acknowledge prior contact
 * Assess main concerns of patient
 * Why are they visiting Genetics today?
 * What do they hope to gain from the session?
 * explore desire to have a diagnosis
 * mother previously mentioned that they had come to terms with not having a diagnosis
 * Overview of today's session
 * Restate patient's concerns
 * Medical history, family history, physical exam, genetics, recurrence risk, testing options and limitations

Pediatric Intake

 * Family History
 * any relatives with hypotonia? developmental delay or learning disabilities? MR? -- no to all
 * history of infant deaths or miscarriages? birth defects? -- no
 * diabetes? cancer? thyroid prolems? heart problems? respiratory problems? genetic conditions? -- no to all
 * consanguinity? -- no

Differential Diagnosis

 * Canavan disease
 * autosomal recessive
 * characterized by developmental delays by age 3-5 months, severe hypotonia involving "head lag", and inability to sit, walk, or speak
 * hypotonia eventually changes to spasticity and help with feeding is necessary
 * macrocephaly
 * Testing
 * urine analysis for concentration of N-acetylaspartic acid (NAA)
 * increased in affected patients
 * blood analysis for levels of aspartoacylase enzymatic activity
 * often unmeasurable in affected patients

Myotonic Dystrophy

 * autosomal dominant
 * incidence of 1/20,000
 * suspected in infants with hypotonia, facial muscle weakness, generalized weakness, club foot, and respiratory insufficiency or failure
 * Mild -- characterized by cataract and mild myotonia
 * Classic -- characterized by muscle weakness and wasting, cataracts, myotonia, cardiac conduction abnormalities
 * Congenital -- hypotonia, severe generalized weakness at birth, often have respiratory problems and early death, MR common
 * Testing
 * DNA analysis is 100% sensitive
 * detects an expansion of the CTG trinucleotide repeat in the DMPK gene (19q13)
 * > 37 repeats is abnormal
 * > 50 repeats are symptomatic
 * > 1000 repeats often seen in congenital type
 * Cerebellar Ataxia
 * most types have onset in adulthood
 * Spinocerebellar Ataxia 7 -- failure to thrive and loss of motor milestones, loss of vision
 * Spinocerebellar Ataxia 8 -- common initial symptoms are scanning dysarthria with a characteristic drawn-out slowness of speech and gait instability, hyperactive tendon reflexes
 * onset can be as early as one year old
 * Testing -- CTA/CTG expansion in the SCA8 gene (13q21) can be detected via DNA analysis
 * Aicardi syndrome
 * X-linked dominant inheritance
 * characterized by the partial or complete absence of the corpus callosum (the structure that links the 2 hemispheres of the brain), infantile spasms, mental retardation, and an ocular abnormality called lacunae (lesions) of the retina of the eyes
 * may be associated with other brain defects such as microcephaly or porencephalic cysts (cerebrospinal fluid-filled cavities or gaps in the brain)
 * onset generally begins between the ages of 3 and 5 months
 * Myasthenia gravis (familial infantile)
 * autosomal recessive
 * characterized by respiratory and feeding difficulties in an infant
 * absence or weakness of the ocular muscles is also characteristic
 * Familial Dysautonomia
 * characteristics include lack of tearing, emotional lability, paroxysmal hypertension, increased sweating, cold hands and feet, corneal anesthesia, erythematous blotching of the skin, and drooling
 * the absence of the fungiform papillae of the tongue is also characteristic
 * scoliosis is often severe and neuropathic joints of the Charcot type may develop
 * Ashkenazi-Jewish heritage is common

Previous Testing

 * chromosomal testing done previously -- results normal

Psychosocial Issues

 * How important is a diagnosis to you?
 * If the visit to Genetics does not result in a diagnosis, what will this mean to you?
 * Are you worried about your child having a "label"?
 * Financial concerns
 * Support Network
 * do attend meeting of "Mother of Special Children" each month
 * support from family? friends? church?
 * Educational concerns

Support Groups and Resources

 * Mothers of Special Children
 * www.mothersofspecialchildren.com
 * meet the second Monday of each month at 7:30
 * Hyde Park Bethlehem United Church
 * Hyde Park and Madison Road


 * Ohio Coalition for the Education of Children with Disabilities
 * www.ocecd.org
 * Director: Margaret Burley
 * Co-Director: Lee Ann Derugen
 * Executive Office
 * 165 West Center Street, Suite 302
 * Marion, OH 43302-3741
 * Phone (740) 382-5452 or (800) 374-2806 (in Ohio)
 * Fax (740) 383-6421
 * E-mail: ocecd@gte.net


 * March of Dimes Birth Defects Foundation
 * 1275 Mamaroneck Avenue
 * White Plains, NY 10605
 * email: resourcecenter@modimes.org
 * internet: http://www.modimes.org
 * Tel: 914-428-7100 888-MODIMES (663-4637)
 * Fax: 914-428-8203