Patterns of Congenital Abnormalities Lecturer of Experimental Embryology

Patterns of Congenital Abnormalities Lecturer of Experimental Embryology Zoology Dept. , Faculty of Science, Mansoura University

Causes of human congenital anomalies

Down syndrome (Trisomy 21) Ø 1: 800 of birth Ø Mental deficiency , heart defects. Ø Round face Ø Short digits Ø Incurving of the fifth digit

Female Trisomy 18 Ø 1: 8000 of birth Ø Mental deficiency Ø Micrognathia , low set ear Ø Growth retardation Ø Second and fifth digit overlapping the third and fourth Ø Short sternum Ø Narrow pelvis

Female with trisomy 13 Ø 1: 25000 of birth Ø Mental deficiency, CNS malformation , microphthalmia Ø Bilateral cleft lip &palate Ø Low set malformed ears Ø Polydactyly Ø Small omphalocoele

Young male with Klinefelter syndrome (XXY trisomy) Ø 1: 1080 of birth Ø Presence of breasts Ø Gynecomastia (excessive development of male mammary glands) Ø Small testes , aspermatogenesis due to hyalinization of seminiferous tubules Ø Less intelligent

Structural chromosomal abnormalities Ø A) Reciprocal translocation Ø B) Terminal deletion Ø C) Ring chromosome Ø D) Duplication Ø E) Paracentric inversion Ø F) Isochromosome Ø G) Robertsonian translocation

Cri-du-chat syndrome Ø Terminal deletion of the short arm end of the chromosome no. 5 Ø Child has a weak catlike cry Ø Mental retardation , microcephaly , heart disease.

Chondroplasia Ø Due to a G to A transition mutation of the fibroplast growth factor receptor 3 gene on chromosome 4 p Ø Short limbs and fingers Ø Normal length of the trunk Ø Bowed legs Ø Relatively large head Ø Depressed nasal bridge Ø Prominent forehead

Fragile X-syndrome Ø A) mentally retarded boy with long face and prominent ears Ø B) his six years old sister mild learning disability, long face crossed-right eye Ø Due to gene mutation

Fatal alcohol syndrome Ø Due to high level of alcohol intake during early pregnancy Ø Thin upper lip , Flat nasal bridge , Short nose , microcephaly Ø Elongated and poorly formed philtrum (vertical groove in median part of upper lip) Ø Mental retardation

Aminopterin-induced abnormalities Ø Is an anti-metabolite drug Ø A) meroanencephaly (partial absence of the brain) Ø B) intrauterine growth retardation, large head, small mandibles, deformed ears, clubhands and clubfoots

Goiter Ø Congenital enlargement of thyroid gland due to anti-thyroid drugs ingested by mother

Cataract and glucoma Ø Ø A) bilateral cataract caused by Rubella virus also have cardiac defect and deafness A B) congenital glucoma caused by Rubella virus with enlarged corneal diameter B

First arch syndrome Ø Due to insufficient migration of neural crest cells into the first pharyngeal arch Ø Defect in the cheek between the auricle and the mouth Ø Hypoplasia of mandibles Ø Macostomia

Sublingual thyroid mass Ø Without evidence of functioning thyroid tissue

Unilateral cleft lip and palate Ø 1 : 1000 births Ø Cleft involve the hard & soft region of palate Ø 60 -80% affected infant are males

Types of cleft lip Ø A , B) Unilateral cleft lip Ø b) Is incomplete Ø C, D) Bilateral cleft lip

Congenital anomalies of the face Ø A) median cleft of the upper lip Ø B) median cleft of the lower lip Ø C) bilateral oblique facial cleft with bilateral cleft lip. (rare) Ø D) macrostomia Ø E) single nostril and microstomia Ø F) bifid nose and incomplete median cleft

Cleft lip Type: External Ø Region/Structure: Mouth / Jaw Ø Definition: Fissure of the upper lip Ø Ø A: Cont. B: Malformed Ø B, C: Bilateral (rabbit) B A CC C

Cleft face Type: External Ø Region/Structure: Face Ø Definition: Fissure of the face and jaw Ø Related Term : Prosoposchisis Ø

Cleft palate Type: External Ø Region/Structure: Mouth / Jaw Ø Definition: Fissure of the palate Ø 1: 2500 birth, commen in females than males Ø

High-arched palate Type: External Ø Region/Structure: Mouth / Jaw Ø Definition : A higher than normal palatal arch Ø

Agnathia Type: External Ø Region/Structure: Mouth / Jaw Ø Definition: Absence of the lower jaw (mandible) Ø Related Term : Agenesis, Aplastic Ø

Mandibular micrognathia Type: External Ø Region/Structure: Mouth / Jaw Ø Definition: Small lower jaw (mandible) Ø Synonym or Related Term : Brachygnathia, Micromandible Ø Ø A : Open eye , B : Misshappen pinna , C : Skin tag B C A

Omphaloceole Ø Result from a median defect of the abdominal muscles, fascia, and skin at the umbilicus Ø Herniation of intra-abdominal structure liver and intestine into the proximal end of the umbilical cord Ø It is covered by a membrane composed of peritoneum and amnion

Omphalocele Ø Ø Ø Type: External Region/Structure: Trunk Definition: Protrusion of intra -abdominal viscera into the umbilical cord with viscera contained in a thin translucent sac of peritoneum and amnion Notes: The condition may present with ruptured sac Related Term : Exomphalos Arrow: Attached Placenta

Gastrochisis Ø The viscera protrude into the amniotic cavity Ø Due to anterior wall (2 -4 cm. ) is split. Ø More commen in male than female. Ø Due to drugs &chemicals.

Horse-shoe kidney Ø Fusions of the inferior poles of the kidneys while they were in the plevis Ø Larger right kidney has bifid ureter Ø 1: 500 birth Ø Normal ascent is prevented

Duplex kidney Ø With 2 ureters and renal pelves Ø Result from incomplete division of the metanephric diverticulum or ureteric bud

Ectopia cordis Ø Cleft sternum Ø Bilateral cleft lip Ø Die in the first days of life from infection, cardiac failure and hypoxemia Ø Extremely rare

Ectopia cordis Type: External Ø Region/Structure: Trunk Ø Definition : Heart displaced outside thoracic cavity due to failure of ventral closure Ø

Local edema Type: External Ø Region/Structure: General Ø Definition : Localized accumulation of fluid Ø

Hemorrhage Ø Type: External Ø Region/Structure: General Ø Definition : An accumulation of extravasated blood

Forked Rib Type: Internal Ø Region/Structure: Vertebral Column Ø

1 Fontanelles and sutures 1) Anterior Fontanelle 2) Posterior fontanelle 3) Posteriolateral (mastoid) fontanelle 4) Anteriolateral (sphenoid) fontanelle 1)Sagittal Suture 4 4 3 2 2)Lamboid Suture 1 1 3)Coronal Suture 4) Frontal (metopic) Suture 2 3

Skeletal system abnormalities Ø Acrania (partial absence of calvaria) Ø Meroanenchphaly (partial absence of the brain), ressult from failure of the cranial end of neural tube to close. Ø Rachishisis (extensive cleft in the vertebral arches of the vertebral column) Ø Myelochisis (severe anomly of spinal corde)

Scaphocephaly Ø Long, narrow, wedge shaped skull due to craniosynostosis (premature closure of the sagittal suture Ø More commen in male than in female.

Acephaly Ø Type: External Ø Region/Structure: Cranium Ø Definition : Absence of the head

Exencephaly Ø Ø Type: External Region/Structure: Cranium Definition: The brain protrudes outside the skull due to absence of the cranial vault Notes : Erosion of brain tissue has not occurred as in Anencephaly

Meningocele Ø Type: External Ø Region/Structure: Cranium Ø Definition : Herniation of meninges through defect in skull

Anasarca Type: External Ø Region/Structure: General Ø Definition : Generalized edema Ø

Amelia and meromelia Ø A) Quadruple amelia (comlete absence of the upper and lower limbs). Ø B, C) meromelia (partial absence) of the upper limb. Ø caused by thalidomide.

Various types of meromelia Ø Partial absence of limbs (disturbance of growth of limb) Ø A) absence of hands and most of fore-arms Ø B) absence of the digits Ø C) absence of the hand Ø D) absence of the fourth and fifth digits, syndactyly of the second and third digit Ø E) absence of third digit, cleft hand Ø F) absence of second and third toes, syndactyly of fourth and fifth toes

Limb anomaly Ø A) brachydactyly Ø B) hypoplasia of the thumb Ø C) polydactyly (fingers) Ø D) polydactyly (toes) Ø E) Partial duplication of the foot Ø F) Partial duplication of the thumb

Polydactyly Showing partial duplication of the right foot & toes Ø Supernumerary digits which is incompletely formed and lack of muscular development Ø

Meromelia Ø Limb reduction Ø Caused by thalidomide ingested during critical period of limb development

Syndactyly Ø Ø Ø 2 nd &3 rd. 1: 2200 birth. More frequent in foot than in hand. It may be Cutaneous or Osseous. May be inherited

Ectrodactyly Type: External Region/Structure: Paw / Digit Ø Definition: Absence of one or more digit(s) Ø Notes: Expected skeletal alterations include absence of all phalanges in each affected digit Ø Related Term : Agenesis, Aplastic, Oligodactyly Ø Forelimb 5 th digit absent. Ø Ø

Limb hyperextension Type: External Ø Region/Structure: Limb Ø Definition : The excessive extension or straightening of a limb or a joint Ø Ø A : Normal , B : Malformed A B

Sirenomelia Type: External Ø Region/Structure: Limb Ø Definition: Fusion of lower limbs Ø Notes: May involve lower torso Ø Related Term : Symelia Ø

Polydactyly Type: External Ø Region/Structure: Paw / Digit Ø Definition: Supernumerary digit(s) Ø

Bowed limb Type: External Ø Region/Structure: Limb Ø Definition: Usually seen as an outward bending of the limb Ø Arrow: Omphalocele Ø

Thread-like tail Type: External Ø Region/Structure: Tail Ø Ø Related Term : Filamentous, Filiform

Narrowed tail Type: External Ø Region/Structure: Tail Ø Related Term : Constricted Ø

Curled tail Type: External Ø Region/Structure: Tail Ø Definition: Curved into nearly a full circle Ø Related Term : Curly Ø

Hooked tail Type: External Ø Region/Structure: Tail Ø Definition : Approximately 180 degree bend or curve of the tail Ø Forelimb postaxial Ø

Open eye Ø Ø Ø Type: External Region/Structure: Eye Definition: Partial or complete deficiency of the eyelid Notes: Eyeball usually visible Related Term : Ablepharia Arrow : Exencephaly

Cyclopia Type: External Region/Structure: Eye Definition: Single orbit; eye's) can be absent, completely or incompletely fused Ø Notes: Nose may be absent or appear as a frontonasal appendage (proboscis) above the orbit Ø Synonym or Related Term : Monophthalmia, Synophthalmia Ø Ø Ø

Malpositioned pinna Type: External Ø Region/Structure: Ear Ø Synonym or Related Term : Displaced, Ectopic, Low set Ø

Short trunk Type: External Ø Region/Organ/Structu re: Trunk Ø

Conjoined twins Ø Ø Ø Type: External Region/Structure: General Definition: Monozygotic twins with variable incomplete separation into two during cleavage or early stages of embryogenesis Notes: Site and extent of fusion may be described Related Term : Double monster

Thank you Dr. A. A. A. Gadallah