Congenital Flashcards
1
Q
What is the male:female ratio for isolated cleft palate?
A
1:2
2
Q
What is the male:female ratio for cleft lip, with or without cleft palate?
A
2:1
3
Q
What is the incidence of congenital hearing loss?
A
???
4
Q
What is the incidence of carcinoma arising in a thyroglossal duct cyst?
A
5
Q
What percent of these require surgical intervention?
A
6
Q
What are the four clinical subtypes ofWaardenburg’s syndrome?
A
- SNHL (20%), heterochromia irides, pigment anomalies, dystopia canthorum.
- As above, without dystopia canthorum (SNHL in >so%).
- 3• Klein-Waardenburg’s syndrome: microcephaly, mental retardation, limb and skeletal abnormalities, in addition to signs of #1.
- 4•Shah-Waardenburg’s syndrome: #2 + Hirschsprung’s disease
7
Q
What are the three clinical subtypes of Usher’s syndrome?
A
- I-Severe-profound hearing loss, absent vestibular function, prepubertal retinitis pigmentosa.
- II-Moderate-severe hearing loss, normal vestibular function, postpubertal retinitis pigmentosa.
- III-Progressive hearing loss.
8
Q
What percent of congenital hearing loses are hereditary?
A
>60%.
9
Q
What is the incidence of cleft lip, with or without cleft palate, in term newborns?
A
1 In 1000.
10
Q
What is the incidence of submucous cleft palate in term newborns?
A
1 In 1200.
11
Q
What is the incidence of isolated cleft palate in term newborns?
A
1 In 2000.
12
Q
What is the incidence of congenital aural atresia?
A
1:10,000-20,000.
13
Q
What percent of children with congenital CMV have hearing loss?
A
10% are born with hearing loss, 10-15% eventually develop hearing loss.
14
Q
What percent of infants with laryngomalacia require surgical treatment?
A
10%.
15
Q
What percent of cases of choanal atresia involve only a mucosal diaphragm or membrane?
A
10%.
16
Q
What are the typical inheritance patterns of nonsyndromic hearing loss?
A
10-20% AD, 75% autosomal recessive (AR), 2-3% X-linked,
17
Q
What percent of infants have a hemangioma by age 1?
A
12%.
18
Q
What percent of gliomas have a fibrous tract connecting to the subarachnoid space?
A
15%.
19
Q
What is the incidence of synchronous airway lesions in children with laryngomalacia?
A
18-20%.
20
Q
What is the incidence ofWaardenburg’s syndrome?
A
1in 4,000 births.
21
Q
Birth trauma accounts for what percent of vocal cord paralysis in children?
A
20% (associated with forceps use and C-section).
22
Q
What percent of cases of congenital vocal cord paralysis are bilateral?
A
20%.
23
Q
What is the recovery rate for idiopathic vocal cord paralysis in children?
A
20%.
24
Q
What percent of Thyroglossal duct cyst contains thyroid tissue?
A
20%.
25
What percent of preauricular pits are bilateral?
20%.
26
What percent of teratomas become malignant?
20%.
27
What is the incidence of hemangiomas in premature infants weighing less than 1000 g?
23%.
28
What is the incidence of facial nerve displacement in congenital aural atresia?
25-30%.
29
What percent of sporadic cases of congenital hearing loss are caused by mutation of the DFNB1 gene on chromosome 13, encoding for Connexin-26?
27%.
30
What percent of congenital cholesteatomas are bilateral?
3%.
31
What percent of the hereditary hearing-loss cases are syndromic?
30%.
32
What percent of these are bilateral?
33%.
33
Which branchial pouch is the thymus derived from?
3rd.
34
What is the chance of producing a cleft-lipped child when one parent is affected?
4%.
35
What is the mean age of presentation for congenital cholesteatoma?
4•5 years.
36
If one parent and one sibling are deaf, what is the risk of hearing loss for subsequent offspring?
40% risk.
37
What percent of cases of choanal atresia are bilateral?
40%.
38
What percent of patients with neurofibromatosis type 1 have acoustic neuromas?
5% and usually unilateral.
39
What percent of Caucasians carry the gene defect for cystic fibrosis?
5%.
40
What percent of patients with branchiootorenal syndrome have hearing loss?
50% (50% mixed, 30% conductive, 20% sensorineural).
41
What percent of patients with a subglottic hemangioma have an associated cutaneous hemangioma?
50%.
42
What percent of children with choanal atresia have other congenital anomalies?
50%.
43
What percent of infants with significant congenital hearing loss will not have risk factors?
50%.
44
What percent of hemangiomas regress by age 7?
70%.
45
What percent of patients with congenital bilateral vocal fold paralysis require tracheotomy?
80%.
46
What percent of children with cleft palate do not require tympanostomy tubes?
8-10%.
47
Between what ages do hemangiomas grow most rapidly?
8-18 months.
48
What percent of patients with neurofibromatosis type 2 have acoustic neuromas?
95% and usually bilateral.
49
What is the most common facial cleft?
A cleft uvula.
50
What is the difference between a complete cleft of the primary palate and that of the secondary palate?
A complete cleft of the primary palate extends into the nose, is always associated with a cleft lip, and does not expose the vomer. A complete cleft of the secondary palate involves both the hard and soft palates, extends into the nose, and exposes the vomer.
51
What is the role of palatal plates in the treatment of cleft palates?
A palatal plate, when worn for 3 months prior to surgery and adjusted weekly to bring the palate and alveolus into a more normal shape, has been shown to lessen closure tension during surgery.
52
What is an incomplete cleft?
A varying amount of midline mucosal attachment is preserved with an underlying muscular deficiency.
53
What is the most common anomaly associated with congenital tracheal stenosis?
Aberrant left pulmonary artery (pulmonary artery sling complex).
54
What is the basic defect of Crouzon's disease?
Abnormal fibroblast growth factor receptors.
55
What is the basic defect causing this syndrome?
Abnormal potassium channels.
56
What is the ciliary defect in patients with Kartagener's syndrome?
Absence of dyne in side arms on A-tubules.
57
Which inner ear aplasia is characterized by high-frequency hearing loss with normal low-frequency hearing?
Alexander.
58
Why does spontaneous CSF otorrhea present late when caused by arachnoid granulations?
Arachnoid granulations become larger with time; the normal pulsation of CSF pressure can cause bony erosion.
59
What is the optimal treatment for port wine stains?
Argon laser in darker-skinned adults; flashlamp pulsed tunable dye laser in children and lighter-skinned adults.
60
What is the most common neurologic condition causing vocal cord paralysis in children?
Arnold-Chiari malformation.
61
What is the typical course of the tract of right-sided 4th branchial cleft cysts?
As above, except they loop around the subclavian artery instead of the aorta.
62
What is the typical course of the tract of 3rd branchial cleft cysts?
Ascend lateral to the common carotid artery, pass posterior to the internal carotid artery, superior to XII, and inferior to IX; course medially to pierce the thyrohyoid membrane superior to the internal branch of the superior laryngeal nerve.
63
Where do most laryngeal webs occur?
At the anterior glottis (75%).
64
What is the typical inheritance pattern of syndromic hearing loss?
Autosomal dominant (AD).
65
What is the inheritance pattern of branchiootorenal syndrome?
Autosomal dominant.
66
What is the inheritance pattern of Treacher-Collins?
Autosomal dominant.
67
What is the typical course of the tract of left-sided 4th branchial cleft cysts?
Begin at the apex of the pyriform sinus, descend lateral to the recurrent laryngeal nerve into the thorax, loop around the aortic arch, ascend to the neck posterior to the common carotid artery, cross XII, descend to open into the skin at the anterior-inferior aspect of the sternocleidomastoid muscle.
68
Where are most 2nd branchial cleft cysts located?
Below the angle of the mandible and anterior to the sternocleidomastoid muscle.
69
Which of these is lethal prenatally?
Blomstrand's chondrodystrophy.
70
What syndrome is characterized by hearing loss, renal defects, and cervical fistula?
Branchiootorenal.
71
What are the clinical features of arteriovenous malformations?
Brightly erythematous lesions of the skin with an associated thrill and bruit.
72
Persistence of what membrane results in choanal atresia?
Buccopharyngeal.
73
What does stenosis of the EAC predispose to?
Canal cholesteatoma.
74
What are the four categories of lymphatic malformations?
Capillary, cavernous, cystic (hygroma), and lymphangiohemangioma.
75
What are the four main types of vascular malformations?
Capillary, venous, lymphatic, and arteriovenous malformations.
76
Which type of vascular malformation is a port wine stain?
Capillary.
77
Which of lymphatic malformations is most commonly found on the tongue or floor of mouth?
Capillary.
78
What further facial deformities often occur as a child with a cleft palate grows?
Collapse of the alveolar arch, midface retrusion, and malocclusion.
79
Which sounds are most difficult for patients with cleft palate?
Consonants, as they require full palatal lift.
80
What disease is characterized by cranial synostosis, exophthalmos, parrot-beaked nose, and hypoplastic mandible?
Crouzon's disease.
81
What is a Thornwaldt's cyst?
Cyst in the nasopharyngeal bursa secondary to persistent embryonic communication between the anterior tip of the notochord and the nasopharyngeal epithelium.
82
Which of lymphatic malformations is associated with location in the posterior triangle of the neck?
Cystic hygroma.
83
What organism is most commonly associated with virus-induced congenital deafness?
Cytomegalovirus (CMV).
84
How can one differentiate a dermoid cyst from a TGDC?
Dermoid cyst will not elevate with tongue protrusion.
85
What are the four types of germ cell tumors?
Dermoid cyst, teratoid cyst, teratoma, and epignathus.
86
Which of these are composed only of mesoderm and ectoderm?
Dermoid cysts.
87
What is the etiology of a type 2 first branchial cleft cyst?
Duplication error of the ectodermal and mesodermal elements of the EAC.
88
What is the etiology of a type 1first branchial cleft cyst?
Duplication error of the ectodermal elements of the EAC.
89
What are the indications for surgical treatment of laryngomalacia?
Dyspnea at rest or during effort, feeding difficulties, and failure to thrive.
90
Which of the four variants of Familial Ataxia Syndrome (Episodic Ataxia) is caused by mutations in a potassium channel gene (KCNA1) on 12p13?
EA1
91
What are the two most common variants of Familial Ataxia Syndrome (Episodic Ataxia)?
EA1 and EA2.
92
Which of the variants of the Familial Ataxia Syndrome (Episodic Ataxia) is associated with vertigo and results from mutations of a calcium channel gene on 19p?
EA2.
93
Which variant of Familial Ataxia Syndrome (Episodic Ataxia) is associated with migraine?
EA2.
94
Of the four variants of Familial Ataxia Syndrome (Episodic Ataxia) (EA1, EA2, EA3, EA4), which one does not respond to acetazolamide?
EA3 or periodic vestibulocerebellar ataxia.
95
What is a congenital cholesteatoma?
Embryonal inclusion of undifferentiated squamous epithelium in the middle ear behind an intact TM, usually with no history of otitis media.
96
What are the three most common congenital midline nasal masses?
Encephaloceles, gliomas, and dermoid cysts.
97
Which of congenital midline nasal masses has an intracerebral connection?
Encephaloceles.
98
What inner ear malformation is associated with early onset sensorineural hearing loss, usually bilateral and progressive, and vertigo?
Enlarged vestibular aqueduct.
99
Which ethnic group has the highest incidence of isolated cleft palate?
Equal incidence among racial groups.
100
What organisms are most commonly cultured from this disorder?
Escherichia coli} Klebsiella} Proteus, and Clostridium.
101
What is the relationship between laryngomalacia and gastroesophageal reflux disease (GERD)?
Essentially all children with laryngomalacia have GERD.
102
What gene is responsible for this syndrome?
EYA1 on chromosome 8q13.3.
103
What is the etiology of a preauricular pit?
Failure of fusion between Hillocks of His 1and 2.
104
What syndrome is characterized by recurrent episodes of vertigo and ataxia in several members of a family?
Familial Ataxia Syndrome (Episodic Ataxia).
105
When is intervention warranted?
For massive, ulcerative, disfiguring lesions; for those that produce hematologic, cardiovascular, or upper aerodigestive tract compromise; and for large periorbital lesions that obstruct vision.
106
What is the function of connexin 26?
Formation of gap junctions in the stria vascularis, basement membrane, limbus, and spiral prominence of the cochlea.
107
What are the boundaries of a unilateral cleft of the primary palate?
From the incisive foramen anteriorly, between the canine and adjacent incisor to the lip.
108
What disorder should be suspected in children with cleft palate who fall below the 5th percentile in growth?
Growth hormone deficiency, as it is 40 times more common in this population.
109
What condition is seen in adolescent patients with severe, frequently recurring epistaxis and pulmonary arteriovenous malformations?
Hereditary hemorrhagic telangiectasia (HHT).
110
What effect does the timing of treatment for Arnold-Chiari have on the outcome of vocal cord paralysis?
If the ICP is normalized within 24 hours, vocal cord function will recover within 2 weeks in most patients.
111
An infant has a left-sided suprahyoid lymphatic malformation. Using the DeSerres classification system, which class is this?
II.
112
Where are most type 1cysts located?
In the periauricular region, lateral to VII, connecting the skin to the EAC.
113
What type of cleft is a submucous cleft palate?
Incomplete cleft of the secondary palate.
114
What is the characteristic nasal deformity in a child with a unilateral cleft lip?
Inferior and posterior displacement of the alar cartilage on the cleft side.
115
What is the most common vascular ring?
Innominate artery compression.
116
What manifestation of congenital syphilis is most commonly related to SNHL?
Interstitial keratitis.
117
Where are most type 2 cysts located?
Just inferior or posterior to the angle of the mandible with variable relationship to VII.
118
What syndrome is characterized by profound thrombocytopenia associated with a hemangioma?
Kasabach-Merritt syndrome.
119
What are the three most common causes of stridor in children?
Laryngomalacia, vocal cord paralysis, and congenital subglottic stenosis.
120
Which lesions respond best to pulsed dye laser?
Lesions less than 20 em2 in children
121
What is the typical severity and pattern of autosomal-dominant hearing loss?
Less severe, delayed onset, high-frequency hearing loss.
122
Which chromosome carries the gene responsible for cystic fibrosis?
Long arm of chromosome 7.
123
Which of lymphatic malformations is associated with episodic bleeding?
Lymphangiohemangioma.
124
Which of lymphatic malformations is more likely to rapidly enlarge during an upper respiratory tract infection?
Lymphangiohemangioma.
125
What prenatal condition is associated with a higher incidence of cervical teratomas?
Maternal polyhydramnios.
126
What is the term for complete agenesis of the petrous portion of the temporal bone?
Michel aplasia.
127
Which inner ear aplasia will not allow cochlear implant or amplification aids?
Michel aplasia.
128
Which lesions are less likely to respond to sclerosis with OK-432 (Picibanil)?
Microcystic, previously operated on, and those with massive craniofacial involvement.
129
What inner ear malformations are more common in patients with Pendred syndrome?
Mondini aplasia and enlarged vestibular aqueduct.
130
What is the term for a developmentally deformed cochlea where only the basal coil can be identified?
Mondini aplasia.
131
What happens to the soft palate muscles in a secondary cleft palate?
Muscle fibers follow the cleft margins and insert into the posterior edge of the remaining soft palate.
132
What happens to the orbicularis oris muscle in a complete cleft lip?
Muscle fibers follow the cleft margins and terminate at the alar base.
133
What happens to the orbicularis oris muscle in an incomplete cleft lip?
Muscle fibers remain continuous but are hypoplastic across the cleft.
134
What gene mutation is behind Familial Ataxia Syndrome (Episodic Ataxia)?
Mutation in a potassium channel gene KCNA1 on 12p13.
135
What genetic mutation is responsible for Treacher-Collins syndrome?
Mutation of TCOF1 on chromosome sq.
136
What is the basic defect causing Alport syndrome?
Mutation of the COL4A5 gene producing the alpha chain of type IV collagen in basement membranes.
137
What genetic mutation is thought to be responsible for 50-60% of all autosomal-recesive hearing loss?
Mutation of the DFNB1gene on chromosome 13q encoding for **connexin 26**.
138
What genetic mutation is responsible for neurofibromatosis type 1?
Mutation of the NF1 gene (nerve growth factor gene) on chromosome 17q11.2.
139
What genetic mutation is responsible for neurofibromatosis type 2?
Mutation of the NF2 gene (tumor suppressor gene) on chromosome 22q12.2.
140
What genetic mutation is responsible for most cases of types 1and 3 of Waardenburg's syndrome?
Mutation of the PAX3 gene on chromosome 2q37.
141
What genetic defect results in either Jansen's chondrodystrophy or Blomstrand's chondrodystrophy?
Mutation of the type 1parathyroid hormone receptor.
142
What genetic mutations are responsible for most cases of Stickler syndrome?
Mutations in the COL2A1 gene on chromosome 12 or the COLIIA2 gene on chromosome 6.
143
What genetic mutations are thought to be responsible for osteogenesis imperfecta?
Mutations of the COLIA1 gene on chromosome 17q and the COLIA2 gene on chromosome 7q.
144
Which ethnic group has the highest incidence of cleft lip?
Native Americans.
145
What are the advantages of using argon plasma coagulation for the treatment of HHT?
Noncontact application, limited and controlled tissue penetration with low risk of septal perforation, no safety measures required (i.e., for lasers), low thermal damage to adjacent tissue, and inexpensive.
146
What is the most common treatment for hemangiomas?
Observation, parental reassurance.
147
What syndrome is characterized by hypertelorism, short stature, broad fingers and toes, cleft palate, and conductive hearing loss?
Otopalatodigital syndrome.
148
What is the most common site of CSF leakage from the inner ear into the middle ear in children?
Oval window (especially in patients with Mondini malformation).
149
What is the typical course of the tract of 2nd branchial cleft cysts?
Pass superiorly and laterally to IX, XII; turn medially to pass between the internal and external carotid arteries; terminate close to the middle constrictor muscle or may open into the tonsillar fossa.
150
What gene is associated with both Pendred syndrome and enlarged vestibular aqueduct?
PDS gene, encoding for pendrin protein, on chromosome 7q31.
151
What is the most common syndromic cause of hearing loss?
Pendred syndrome, accounting for 10% of cases.
152
What is the etiology of Thyroglossal duct cyst?
Persistence of the connection between the base of tongue (foramen cecum) and the descended thyroid gland.
153
What is the etiology of cervical thymic cysts?
Persistence of the thymopharyngeal duct.
154
Other than the middle ear, where else may congenital cholesteatomas arise?
Petrous apex, cerebellopontine angle, mastoid, EAC.
155
What is platybasia?
Phenotypic characteristic of Velocardiofacial syndrome (VCFS) where the cranial base is angled obtusely, resulting in expanded velopharyngeal volume and incomplete velopharyngeal closure.
156
What is thought to cause congenital malleus ankylosis?
Poor development of the epitympanic space leaves the head of the incus and malleus in close contact with the tegmen; a bony bridge can result between the epitympanum and the head of the malleus.
157
What are the most common environmental causes for clefts?
Poorly controlled maternal diabetes and amniotic band syndrome.
158
What is the most common vascular malformation?
Port wine stain.
159
Where exactly are most subglottic hemangiomas located?
Posterolaterally and submucosally.
160
What are the two types of congenital defects that lead to spontaneous CSF otorrhea?
Preformed bony pathway around the bony labyrinth, often associated with a meningocele and aberrant arachnoid granulations located over a pneumatized area of the skull.
161
Which of these is associated with meningitis?
Preformed bony pathway around the bony labyrinth.
162
What is the typical severity and pattern ofX-linked hearing loss?
Prelingual and more clinically diverse hearing loss.
163
How does the defect caused by arachnoid granulations usually present?
Presents after age so as unilateral serous otitis which is at first recurrent and then persistent.
164
What are the three modes of supraglottic obstruction causing laryngomalacia?
Prolapse of the mucosa overlying the arytenoids, foreshortened aryepiglottic folds, and posterior displacement of the epiglottis.
165
What are the clinical features of Jervell and Lange-Nielsen's syndrome?
Prolonged QT interval, syncope, sudden death, and hearing loss.
166
What inflammatory disease is associated with 3rd and 4th branchial anomalies in children?
Recurrent acute suppurative thyroiditis.
167
What is the optimal treatment of malleus fixation?
Removal of the head of the malleus and interposition of the incus between the manubrium and the stapes head.
168
What is the most common form of inner ear aplasia?
Scheibe aplasia (cochleosaccular dysplasia or pars inferior dysplasia).
169
Feeding difficulties are most severe with which type of cleft?
Secondary palate clefts (either isolated or in combination with clefts of the lip and primary palate).
170
What is dystopia canthorum?
Shortened and fused medial eyelids resulting in small medial sclera, lateral displacement of the inferior puncta, and hypertelorism.
171
What are the clinical features of Alport syndrome?
SNHL and renal failure (presenting as hematuria).
172
What are the three classic findings of congenital rubella syndrome?
SNHL, cataracts, heart malformations.
173
What are the typical clinical features of venous malformations?
Soft, compressible, nonpulsatile masses most commonly found on the lip or cheek within the head and neck; also can be found within the masseter muscle or mandible.
174
What strategies can be used to assist feeding with a cleft palate?
Specialized nipples, upright feeding to minimize nasal regurgitation, palatal plates.
175
Which portion of the ossicular chain is least likely to be malformed in patients with congenital aural atresia?
Stapes footplate. Because it develops from the otic capsule.
176
What syndrome is characterized by cleft palate, micrognathia, severe myopia, retinal detachments, cataracts, marfanoid habitus, and hearing loss?
Stickler.
177
What syndrome is characterized by capillary hemangiomas along the distribution of Vt with concomitant capillary, venous, and arteriovenous malformations of the leptomeninges?
Sturge-Weber syndrome.
178
Where are dermoid cysts most commonly found in the head and neck?
Submental area.
179
Which semicircular canal (SCC) forms first? Last?
Superior canal forms first; lateral canal forms last.
180
What is Simonart's band?
The bridge of tissue connecting the central and lateral lip in an incomplete cleft lip.
181
What differentiates a teratoid cyst from a teratoma?
The germ layers are well differentiated in teratomas such that recognizable organs may be found within the masses.
182
What do Keams-Sayre, MELAS, MERRF, and Leber's hereditary optic neuropathy all have in common?
They are all mitochondrial disorders with varying degrees of hearing loss.
183
What is the term for the connection of the 3rd branchial pouch to the thymus gland as the gland descends into the thorax?
Thymopharyngeal duct.
184
What is the commonest midline neck mass in a child
Thyroglossal duct cyst (TGDC)
185
What is the differential diagnosis of a midline neck mass in a child?
Thyroglossal duct cyst (TGDC), dermoid cyst, ectopic thyroid tissue, lymphadenopathy, lipoma, hemangioma, and fibroma.
186
Why do some people recommend radioisotope scanning or ultrasound of the thyroid gland prior to removal of a thyroglossal duct cyst?
To prevent inadvertent removal of the only functioning thyroid tissue.
187
What disease is characterized by lower lid colobomas, downward slanting palpebral fissures, hypoplastic mandible, malformations of the external ear, cleft palate, and hearing loss?
Treacher-Collins.
188
What protein does TCOF1 on chromosome sq gene produce?
Treacle.
189
What is the most common single gene transmission error causing clefts?
Trisomy 21.
190
True/False: Frontal sinus hypoplasia is common in patients with cystic fibrosis.
True.
191
True/False: 1in 31people are carriers for the connexin 26 mutation.
True.
192
True/False: Superior SCC deformities are always accompanied by lateral SCC deformities.
True.
193
True/False:The mastoid bones of patients with congenital cholesteatoma are most often well aerated.
True.
194
True/False: Histologically, the bony structures are normal, without evidence of otosclerosis, in cases of malleus ankylosis.
True.
195
Which type of neurofibromatosis is characterized by cutaneous neurofibromas?
Type 1.
196
What syndrome is characterized by SNHL and retinitis pigmentosa?
Usher's syndrome.
197
When is the typical onset of symptoms in patients with subglottic hemangioma?
Usually asymptomatic at birth and symptomatic by 6 months of age.
198
What is the name for the subtype of osteogenesis imperfecta in which progressive hearing loss begins in early childhood?
Van der Hoeve's syndrome.
199
What are the clinical differences between a hemangioma and a vascular malformation?
Vascular malformations are present at birth, grow proportionately with the child, and are associated with distortion or destruction of surrounding bone or cartilage; hemangiomas generally emerge after birth, proliferate and then regress, and do not affect surrounding bone or cartilage.
200
What are the two most commonly used classification systems for clefts?
Veau and Iowa classifications.
201
What syndrome is characterized by hypernasal speech, cardiac malformations, cleft palate, and medial displacement of the carotid arteries?
Velocardiofacial syndrome (VCFS).
202
What syndrome, characterized by deletion of band 11 on the long arm of chromosome 22, is a contraindication to adenoidectomy?
Velocardiofacial syndrome (VCFS).
203
What is the characteristic feature of a teratoid cyst?
Very poor differentiation of all three germ layers.
204
What syndrome accounts for the most common form of hereditary congenital deafness?
Waardenburg's syndrome.
205
What are the indications for definitive treatment of lymphatic malformations?
When vital structures are endangered, when episodic hemorrhage occurs, or if macroglossia is present.
206
What X-linked syndrome is associated with the Klippel-Feil syndrome, SNHL, and cranial nerve VI paralysis?
Wildervanck syndrome.
207
What is Norrie syndrome?
X-linked disease characterized by blindness, progressive mental retardation, and hearing loss.
