Sex Chromosome Disorders Test 2 Flashcards
Turner Syndrome
Pathophysiology
45XO (gondal dysgenesis)
Turner Syndrome
Incidence
1: 2,500 female births, no correlation to advanced maternal age or paternal link
- most common chromosome cause of spontaneous abortions or miscarriage
Turner Syndrome physical features
- webbed neck
- cubital valgus
- dorsal edema of hands and feet
- hypertelorism (wide set eyes)
- epicanthal folds
- ptosis( dropping eyelids)
- elongated ears
- growth retardation
Turner Syndrome
other systems effected
- congenital heart disease( septal defects, heart valve issues)
- kidney malfunction
- hearing loss
- decreased gustatory and olfaction
- deficits in spatial perception and orientation ( problems w/ motor function)
- average intellect in most
- sexual infantilism-don’t develop secondary sex characteristics (breasts, infertile)
Turner Syndrome -skeletal abnormalities
- hip dislocation
- foot deformities
- osteoporosis-low estrogen levels-managed w/ meds
- idiopathic scoliosis- no known cause
Klinefelter syndrome
47XXY
- increased levels of estrogen
Incidence of Klinefelter syndrome
1:1,000
Clinical Pic of Klinefelter syndrome
- testes fail to enlarge
- gynecomastia (male breast development)
- normal IQ
- sterility
Klinefelter syndrome ( severe karotypes)
- severe MR
- microcephaly
- hypertelorism (wide set eyes)
- strabismus
- celft palate
- radioulnar stenosis (limitations in pronation and supination
- genu valgus
- malformed cervical vertebrae( alignment /posture issue)
- pes planus
Fragile X disease pathophysiology
structural abnormality of the X chromosome
- in females the 2nd X can compensate for abnormaility
Fragile X disease incidence
1:1,200 carried on in males
Clinical features of Fragile X disease
- large head/ears/jaw
- myopia (hard to see far away)
- V-shaped palate
- large testes
- active/autistic ( hyperactive
- not any major health issues -may be on track with motor development
Partial Deletion of chromosome
- a section of a chromosome is missing
- often has be been deleted in the replication process during meiosis (gametogenesis)
- named by chromsosome # and location of deletion on the long or short arm (Q-long, P-short)
- deletion may be on any autosome
Partial deletion Syndromes
- Wolf-Hisrchhorn syndrome
- Cri-du-Chat Syndrome
- Prader Willi Syndrome
Wolf-Hisrchhorn syndrome pathophysiology
- partial deletion syndrome
- 46XY-4P or 46XX-4P
Wolf-Hisrchhorn syndrome prevalance
120 cases as of 1992, 2010 ~500 individuals in US
Clinical features of Wolf-Hisrchhorn syndrome
-severe psychomotor and growth retardation
-hypertonicity
- seizures
-microcephaly
-hypertelorism
-cleft lip/palate
-heart malformation
-hip dislocation
-club feet ( PF, supination, Inversion)
(physical and cognitive features)
Cry-du-Chat syndrome pathophysiology
- partial deletion syndrome
- 46XY-5p or 46XX-5p
Incidence of Cry-du-Chat syndrome
1:20,000
Clinical features of Cry-du-Chat syndrome
-high pitched cat like cry
-microcephaly
-intrauterine growth retardation
-hyperteleorism
-strabismus
-low set ears
-severe MR
- tone abnormalities ( typically increased)
-scoliosis
-hip dislocation
-club feet
-mid-line hair (synapharies)
-hyper-extensible fingers/toes ( increased lig. laxity)
respiratory and feeding problems
(typically very involved indiv. -PT works with positioning for breathing and feeding)
Prader Willi Syndrome pathophysiology
-partial deletion syndrome
46XY-15q or 46XX-15q
Incidence of Prader Willi Syndrome
1:10,000
Early Clinical features of Prader Willi Syndrome
- hypotonia,
-expressionless face
-weak cry
-poor feeding
-slow weight gain
-dysmorphic facial features
( may have dx of FTT, uninterested in environment, oral motor issues
typically able to but delayed motor skills; walking running etc
may have cognitive issues throughout life)
Late Clinical features of Prader Willi Syndrome
- improved mm tone w/ coordination and motor delays
- persistent/ compulsive appetite ( hyperphagia- overactive eating (food & nonfood substances))
- obesity
- hypogonadism (don’t develop sexually- male or female)
- mild/moderate MR
- maladapive behaviors( self-injury( head banging, picking, biting)