Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

4th year passmedicine by topic > Genetics Child Health > Flashcards

Genetics Child Health Flashcards

(102 cards)

Start Studying
1
Q

Autosomal recessive conditions are often thought to be ‘metabolic’ as opposed to autosomal dominant conditions being ‘structural’

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The following conditions are autosomal dominant

A

Huntington’s disease
Myotonic dystrophy
Osteogenesis imperfecta
Von Willebrand’s disease - except T3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The following conditions are autosomal recessive

A

Cystic fibrosis
Gilbert’s syndrome
Haemochromatosis
Sickle cell anaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In X-linked recessive inheritance only males are affected

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

In X-linked recessive inheritance only males are affected - exception

A

Turner’s syndrome, who are affected due to only having one X chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

X-linked recessive
Each male child of a heterozygous female carrier has a ?% chance of being affected whilst each female child of a heterozygous female carrier has a ?% chance of being a carrier.

A

Each male child of a heterozygous female carrier has a 50% chance of being affected whilst each female child of a heterozygous female carrier has a 50% chance of being a carrier.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

X-linked recessive - possibility of an affected father having children with a heterozygous female carrier is generally speaking extremely rare

A

true
However, in certain Afro-Caribbean communities G6PD deficiency is relatively common and homozygous females with clinical manifestations of the enzyme defect are seen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The following conditions are inherited in a X-linked recessive fashion

A

Duchenne muscular dystrophy
G6PD deficiency
Haemophilia A,B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The following conditions are inherited in a X-linked dominant fashion

A

Alport’s syndrome
Rett syndrome
Vitamin D resistant rickets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Inheritance pattern of - Achondroplasia

A

autosomal dominant disorder

In most cases (approximately 70%) it occurs as a sporadic mutation

It is caused by a mutation in the fibroblast growth factor receptor 3 (FGFR-3) gene. This results in abnormal cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Achondroplasia sx

A

short limbs (rhizomelia) with shortened fingers (brachydactyly)
large head with frontal bossing and narrow foramen magnum
midface hypoplasia with a flattened nasal bridge
‘trident’ hands
lumbar lordosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Achondroplasia main risk factor

A

advancing parental age at the time of conception. Once present it is typically inherited in an autosomal dominant fashion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Achondroplasia mx

A

There is no specific therapy.

some individuals benefit from limb lengthening procedures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Down’s syndrome features - face

A

upslanting palpebral fissures, epicanthic folds, Brushfield spots in iris, protruding tongue, small low-set ears, round/flat face
flat occiput

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Down’s syndrome features - hands and feet

A

single palmar crease, pronounced ‘sandal gap’ between big and first toe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Down’s syndrome features hyper/hypotonia

A

hypotonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Down’s syndrome features which cardiac complications?

A

congenital heart defects (40-50%)

multiple cardiac problems may be present
endocardial cushion defect
ventricular septal defect (c. 30%)
secundum atrial septal defect (c. 10%)
tetralogy of Fallot (c. 5%)
isolated patent ductus arteriosus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Down’s syndrome features which atresia

A

duodenal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Later complicactions of Down’s syndrome - describe fertility issues

A

males are almost always infertile due to impaired spermatogenesis. Females are usually subfertile, and have an increased incidence of problems with pregnancy and labour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Later complicactions of Down’s syndrome which infections?

A

repeated respiratory infections (+hearing impairment from glue ear)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Later complicactions of Down’s syndrome which dementia?

A

Alzheimer’s disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Later complicactions of Down’s syndrome hyper/hypothyroidism

A

hypothyroidism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Later complicactions of Down’s syndrome causes atlantoaxial instability

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Later complicactions of Down’s syndrome - which leukaemia?

A

acute lymphoblastic leukaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Duchenne muscular dystrophy is associated with which cardiac complication
dilated cardiomyopathy
26
Duchenne muscular dystrophy causes calf hypertrophy
false | calf pseudohypertrophy
27
Duchenne muscular dystrophy 30% of patients have intellectual impairment
true
28
Fragile X syndrome is a
trinucleotide repeat disorder.
29
Fragile X syndrome Features in males | - face
large low set ears, long thin face, high arched palate
30
Fragile X syndrome Features in males | micro/macro orchidism
macroorchidism
31
Fragile X syndrome Features in males | hyper/hypotonia
hypotonia
32
Fragile X syndrome - cardiac issues
mitral valve prolapse
33
Features in females (who have one fragile chromosome and one normal X chromosome) range from normal to mild
true
34
Fragile X syndrome diagnosis cannot be made antenatally
false | can be made antenatally by chorionic villus sampling or amniocentesis
35
Fragile X syndrome diagnosis based analysis of
number of CGG repeats using restriction endonuclease digestion and Southern blot analysis
36
Gene & Associated cancers | - p53
Common to many cancers, Li-Fraumeni syndrome
37
Gene & Associated cancers | - APC
Colorectal cancer
38
Gene & Associated cancers | - BRCA
Breast and ovarian cancer
39
Gene & Associated cancers | - NF1
Neurofibromatosis
40
Gene & Associated cancers | - Rb
Retinoblastoma
41
Gene & Associated cancers | - WT1
Wilm's tumour
42
Gene & Associated cancers | - Multiple tumor suppressor 1 (MTS-1, p16)
Melanoma
43
Turner's syndrome | is caused by?
resence of only one sex chromosome (X) or a deletion of the short arm of one of the X chromosomes. Turner's syndrome is denoted as 45,XO or 45,X.
44
Turner's syndrome - cardiac complication?
bicuspid aortic valve (15%), coarctation of the aorta (5-10%)
45
Turner's syndrome - gonadotrophin levels will be elevated/low
elevated
46
Turner's syndrome causes lymphoedema in neonates (especially feet)
true
47
Whilst most DNA is found in the cell nucleus, a small amount of double-stranded DNA is present in the mitochondria. It encodes
protein components of the respiratory chain and some special types of RNA
48
Mitochondrial inheritance inheritance is only via
the maternal line as the sperm contributes no cytoplasm to the zygote
49
Mitochondrial inheritance none of the children of an affected male will inherit the disease all of the children of an affected female will inherit the disease
true
50
heteroplasmy is
poor genotype:phenotype correlation - within a tissue or cell there can be different mitochondrial populations
51
Mitochondrial diseases histology?
muscle biopsy classically shows 'red, ragged fibres' due to increased number of mitochondria
52
Mitochondrial diseases examples?
``` Leber's optic atrophy MELAS syndrome MERRF syndrome Kearns-Sayre syndrome sensorineural hearing loss ```
53
MELAS syndrome features?
mitochondrial encephalomyopathy lactic acidosis and stroke-like episodes
54
MERRF syndrome features?
myoclonus epilepsy with ragged-red fibres
55
Kearns-Sayre syndrome features?
onset in patients < 20 years old, external ophthalmoplegia, retinitis pigmentosa. Ptosis may be seen
56
Trinucleotide repeat disorders are
genetic conditions caused by an abnormal number of repeats (expansions) of a repetitive sequence of three nucleotides
57
Trinucleotide repeat disorders are usually
neurological disorders
58
Trinucleotide repeat disorders examples?
``` Fragile X (CGG) Huntington's (CAG) myotonic dystrophy (CTG) Friedreich's ataxia* (GAA) spinocerebellar ataxia spinobulbar muscular atrophy dentatorubral pallidoluysian atrophy ```
59
Trinucleotide repeat disorders may lead to an earlier age of onset in successive generations due to?
expansions are unstable and may enlarge | phenomenon known as anticipation
60
Key features of Patau syndrome (trisomy 13)
Microcephalic, small eyes Cleft lip/palate Polydactyly Scalp lesions
61
Key features of Edward's syndrome (trisomy 18)
Micrognathia Low-set ears Rocker bottom feet Overlapping of fingers
62
Key features of Fragile X
``` Learning difficulties Macrocephaly Long face Large ears Macro-orchidism ```
63
Key features of Noonan syndrome
Webbed neck Pectus excavatum Short stature Pulmonary stenosis
64
Key features of Pierre-Robin syndrome
Micrognathia Posterior displacement of the tongue (may result in upper airway obstruction) Cleft palate
65
Key features of Prader-Willi syndrome
Hypotonia Hypogonadism Obesity
66
Key features of William's syndrome
``` Short stature Learning difficulties Friendly, extrovert personality Transient neonatal hypercalcaemia Supravalvular aortic stenosis ```
67
Key features of Cri du chat syndrome (chromosome 5p deletion syndrome)
Characteristic cry (hence the name) due to larynx and neurological problems Feeding difficulties and poor weight gain Learning difficulties Microcephaly and micrognathism Hypertelorism
68
Prader-Willi syndrome is an example of genetic imprinting where the phenotype depends on whether the deletion occurs on a gene inherited from the mother or father:
Prader-Willi syndrome if gene deleted from father | Angelman syndrome if gene deleted from mother
69
Prader-Willi syndrome is associated with the absence of the active Prader-Willi gene on the long arm of chromosome 15. This may be due to:
microdeletion of paternal 15q11-13 (70% of cases) | maternal uniparental disomy of chromosome 15
70
Prader-Willi syndrome causes anorexia
false | childhood obesity
71
McCune-Albright syndrome is not inherited
True | it is due to a random, somatic mutation in the GNAS gene.
72
McCune-Albright syndrome - Features
precocious puberty cafe-au-lait spots polyostotic fibrous dysplasia short stature
73
What is Often thought of as the 'male Turner's'?
Noonan syndrome
74
Noonan syndrome is thought to be caused by
a defect in a gene on chromosome 12
75
Noonan syndrome characteristic clinical signs
``` cardiac: pulmonary valve stenosis ptosis triangular-shaped face low-set ears coagulation problems: factor XI deficiency ```
76
William's syndrome is
inherited neurodevelopmental disorder caused by a microdeletion on chromosome 7
77
William's syndrome sx
``` elfin-like facies characteristic like affect - very friendly and social learning difficulties short stature transient neonatal hypercalcaemia supravalvular aortic stenosis ```
78
William's syndrome diagnosis
FISH studies
79
Phenylketonuria (PKU) is
is an autosomal recessive condition caused by a disorder of phenylalanine metabolism. This is usually due to defect in phenylalanine hydroxylase, an enzyme which converts phenylalanine to tyrosine
80
High levels of phenylalanine lead to problems such as
learning difficulties and seizures
81
Phenylketonuria sx
usually presents by 6 months e.g. with developmental delay child classically has fair hair and blue eyes learning difficulties seizures, typically infantile spasms eczema 'musty' odour to urine and sweat*
82
Phenylketonuria diagnosis
Guthrie test: the 'heel-prick' test done at 5-9 days of life - also looks for other biochemical disorders such as hypothyroidism hyperphenylalaninaemia phenylpyruvic acid in urine
83
Phenylketonuria mx
dietary restrictions are however important during pregnancy as genetically normal fetuses may be affected by high maternal phenylalanine levels
84
hypochromic and microcytic, but the Hb level would be typically normal suggests which alpha thalassemia?
1 or 2 alpha globulin alleles are affected
85
hypochromic microcytic anaemia with splenomegaly suggests which alpha thalassemia?
Hb H disease | 3 alpha globulin alleles are affected
86
death in utero (hydrops fetalis, Bart's hydrops) suggests which alpha thalassemia?
4 alpha globulin alleles are affected (i.e. homozygote)
87
High LH Low Testosterone - Which disorder of sex hormones?
Primary hypogonadism (Klinefelter's syndrome)
88
Low LH Low Testosterone - Which disorder of sex hormones?
Hypogonadotrophic hypogonadism (Kallman's syndrome)
89
High LH Normal/high Testosterone - Which disorder of sex hormones?
Androgen insensitivity syndrome
90
Low LH High Testosterone - Which disorder of sex hormones?
Testosterone-secreting tumour
91
Klinefelter's syndrome is associated with karyotype
47, XXY
92
Klinefelter's syndrome features?
``` often taller than average lack of secondary sexual characteristics small, firm testes infertile gynaecomastia - increased incidence of breast cancer ```
93
Kallman's syndrome is a recognised cause of delayed puberty secondary to hypogonadotrophic hypogonadism. It is usually inherited as
X-linked recessive trait
94
Kallman's syndrome is thought to be caused by
failure of GnRH-secreting neurons to migrate to the hypothalamus.
95
Androgen insensitivity syndrome is an
X-linked recessive condition due to end-organ resistance to testosterone causing genotypically male children (46XY) to have a female phenotype
96
Androgen insensitivity syndrome | features
'primary amenorrhoea' undescended testes causing groin swellings breast development may occur as a result of conversion of testosterone to oestradiol
97
Androgen insensitivity syndrome diagnosis
buccal smear or chromosomal analysis to reveal 46XY genotype
98
Androgen insensitivity syndrome management
``` counselling - raise child as female bilateral orchidectomy (increased risk of testicular cancer due to undescended testes) oestrogen therapy ```
99
Homocystinuria is
a rare autosomal recessive disease caused by a deficiency of cystathionine beta synthase. This results in severe elevations in plasma and urine homocysteine concentrations.
100
Homocystinuria Features
often patients have fine, fair hair musculoskeletal Marfanoid body habitus: arachnodactyly etc osteoporosis kyphosis neurological: may have learning difficulties, seizures ocular downwards (inferonasal) dislocation of lens severe myopia increased risk of arterial and venous thromboembolism also malar flush, livedo reticularis
101
Homocystinuria ix
increased homocysteine levels in serum and urine | cyanide-nitroprusside test: also positive in cystinuria
102
Homocystinuria mx
Treatment is vitamin B6 (pyridoxine) supplements.

4th year passmedicine by topic (96 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions